GEOLOGICAL SURVEY CIRCULAR 135 

ABSTRACTS OF THE LITERATURE 

ON SYNTHESIS OF APATITES AND 

SOME RELATED PHOSPHATES 

By Elizabeth B. Jaffe 
UNITED STATES DEPARTMENT OF THE INTERIOR 

Oscar L. Chapman, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

Washington, D. C. 

Free on application to the Geological Survey, Waahington 25, D. C. 
UNITED STATES DEPARTMENT OF THE INTERIOR 

O~L.Chapman,S~auy 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CIRCULAR 135 

ABSTRACTS OF THE LITERATURE ON SYNTHESIS OF 

APATITES AND SOME DELATED PHOSPHATES 

By 

Elizabeth B. Jaffe 

Washington, D. C., 1951 

Free on application to the Geological Survey, Washington 26, D. C. 

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CONTENTS 

Introduction • . • • • . • 

Discussion and suggestions o 

Abstracts •• 

Author index • ~ • • • 0 

TABLES 

Table l. Apatites synthesized by previous workers 

2. Lattice constants of synthetic apatites •. 

Page 

l 

II • • • 16 

0 19 

. 77 

Page 

. . . 3 

. . 13 

3. Optical constants of synthetic apatites. • • 15 

ABSTRACTS OF THE LITERATURE ON SYNTHESIS OF 

APATITES AND SOME RELATED PHOSPHATES 

By Elizabeth B. Jaffe 

INTRODUCTION 

The apatite group of minerals has been studied from 

the point of view of the physiologist, biochemist, or 

soils scientist, as well as from -that of the geologist 

or mineralogist. Although all these people have had 

the same problems, they have not always been sufficiently 

acquainted with each other's work; the present collection 

of selected abstracts is intended to clear the way for 

those who are concerned with the synthesis of apati~es 

and related phosphates. Following tables 1, 2, and 3, 

which give a brief summary of the syntheses of apatite 

attempted by previous workers, is a short discussion of the 

problems encountered in the synthesis of the minerals of 

the apatite group. 

This work was completed as part of a program undertaken by the Geological Survey on behalf of the Atomic 

Energy Commission. The author is indebted to T. Botinelly 

(T.B.) and Z. S. Altschuler (Z.S.A.), of the Geological 

Survey for their aid in compilation of abstracts, and to 

Earl Ingerson, Michael Fleischer, and Jane Titcomb, also of 

the Geological Survey, and Z. S. Altschuler, for their 

careful review of this paper. 

In table 1, like 

example chlor-, fluor-, 

together. Within each 

varieties of apatite, for 

carbonate- are grouped 

group, apatites synthesized 
2. 

by wet ethods precede those s,nthesizecl b7 c:1:ey methods, and calciua 

apatites precede those ot otlter •tala. BeJOD.4 this, SJBtlleses are 

listed iD. chronological. order, beghuiimg Y.ltll the aost receat. lfhis 

relatively silr,pl.e elassif'ieatiou. •s ued 'because data 1D. the orig1••' 

papers were too otten inadequate tor a aore elaborate one. ~ aethod 

and reagents used tor each synthesis are briefly Sl8111Lrized. Data 011. 

which identificatioa of apatites is based are given thus: opt = optical 

identification; ehem = partial or e011;plete chellical analysis; X-ray • 

examination of the solid product by x-ray diffraction aethods.J pH = 

measurement of the pH of the liquid phase, either duri.ns or after precipitation, or both; spec = qualitative or semiquaatitative spectrographic analysis; pption = precipitation by metathesis; hydrol. = precipitation by hydrolysis; formulas of the apatites and mineral and 

element names are given throughout as in the origin.al papers, as, for 

example, "Di" (didymium), which has been shown to consist of the elements 

neodymium and praesiodymium. The initials preceding the year at the 

end of eaeh J.isting are those ot the authors Whose papers are summarized. 

Papers on apatite synthesis lJilich appeared in the 19th and early 20th 

centuries have not been abstracted; the more important ones are reported 

in the Data of Geochemistry, whose section on apatite is quoted here on 

the first page of Abstracts. Bone of the synthese~ reported in the Data 

of Geochemistry has been included in the table. 
Table 1.--Apatites synthesized by previous workers. 

Mineral 

Hydroxylapatite 

Hydroxylapatite 

Hyd.roxylapati te 

Hydroxylapatite 

Hydroxylapatite 

Hydroxylapatite 

Hydroxylapatite 

Hydroxylapatite 

H)'droxylapati te? 

Hydroxylapatite? 

Hydroxylapatite? 

Hydroxylapatite? 

Hyaroxyla:pati te 

Hydroxylapatite 

Method 

pption 

pption 

pption 

pption 

pption 

hydrol 

hydrol 

hydrol 

hydrol 

hydrol 

hydrol 

Reagents 

Hz!r:oxylal;tites 

Wet met ods 

Ca hydroxylapatites 

Ca acetate, (NH1 )3 P04 , NH4 acetate 

H:3P04 and C&(OH.J2 sols (dried at .J.l00°) 

HsP04 and Ca ( OH) 2 sols. 

Ca4Pa08Cl2 and steam 

da4?2 o8Cl2 , 1 N NaOH, in closed tube 

B3P04-and Ca(OH) 2 sols. 

CaO in HsP04; Ca(OH)2 sol. 

··l, 

caa (PO,.) 2 in va·ter 

CaHP04 in warm water 

Ca4Pa0s in water 

C&s (P04) a1 KOH, water, CO a atmosphere 

~ or 1 cas(P04)a 

N&sP04, Ca(N03 ) 2 , excess of JB40H 

Cas(PO_.J2 in neutral ammoriium citrate solo 

Time and 

temp in °C 

100° 

100° 

900°,4 hrs 

100° 1 10 days 

25 .. ~····slowly 

mixed 

500hrs 

Checked by 

chemX-ray 

x-ray 

X-ray 

x-ra7 

x-ra)" 

Ref'ere.nce 

.A 50 

cw 50 

cw 49 

It 41 

X Ji.l 

ch•,X-ray ,plQ P 37 

ehem,X-ray,pBI Ia 37 

chea 

x-ra)" 

Sl '' 

SSI: 32 

x-ray 1 SSI: 32 

chea,X-ray SSK 32 

X-ray Br.r 32 

chea,X-ray e 32 

cha,X-ray BHJJ 31. 

I 

\Jrl 
Table 1.--Continued 

·JiiDeral I Method I ,, Reagents Time and 1 Checked by- I Reference 

temp in •c 

3C&s(P04)a•Ca(OH)a hydrol ·Cas(P04)2 in water, or 0.5M or 0.05M NaOH chem. I LTW 29 

Hydroxylapatite pption chem I B 17 

Fluor-hydroxylapatite pption · HsP04, Ca.(OH)2, NaF. or HF sols. 25° chem,opt Ka 50 

ca-Pb hydroxylapatites 

(Ca,Pb)1o(P04)e(OH)2 hy-drol (Ca,Pb)(NOa)2,KH2P04,NaOH bo111Ds I chem,X-ray I M 47 

from Ca10 to Pb1o l.5 hrs 

Sr hydroJt7lapat1tes 

Sr hydroxylapatite I hydrol I SrBP04 in B/10 NaOH 4o• I chem,X-ray I K 39 

Sr hydroxylapatite 1 hydrol I SrHP04 in phosphate 'buf'ter sol. of pH 11.0 4()• I chem.,X-ray I K 39 ..... Sr hydro:qlapatite pption NaOH, BasP04, SrCl2 boiling I chem,X-ray I K '9 

3Srs(P04)a•Sr(OH)2 Srs(P04)2, SrC03 , steam 7 hrs ,1150• I. chem,X-ray I 1C 39 

3Srs(P04)2•Sr(OR)2 hydrol Srs (P04) 2 in water or 0 .5M or 0.0511 BaOB I chem I LW 29 

Dr7 •tho4a 

Ca hydroxylapatites 

Hydroxylapatite I I brushite and cao 900° x-ray, opt. I DBM 49 

Hydroxylapatite I fu.s;ion I Cas(P04)2, Ca~2os, humidity ot air uoo• X-ray 1 chea I K!l' ·32 

Hydroxylapatite I tusion I C&4P20e in air x-r•7 !' 32 

Hydroxylapatite I fusion I a caa (PO") 21 cao, liumidi ty ot air x~ra7 I BFF 32 

l!~!'"""T, ~-.,l\ti t-, I 'f'lqi"n l ~A\ ~,'P -f)-a ( ~·,J~.,-, ~OWl t".a'l ( ~ •) -z •ft,.t\ · ;C•,t)) I ~-~~ I SST{ 'J12 
Table 1.--Continued 

Mineral Method Reagents Time and Checked by Reference 

temp in °C 

Ox;x!~atites 

Dry methods 

Ca. oxyapa.tites 

Hydroxyl-oxyapatite fusion Ca4P2 09 , deficiency of water 1400° x-ray,chem BFF·;; 

3Ca3P20e•CaO . ~- ··~(l'G4)e and Ca.O .dr;ied at 950° x-ray BD 49 

O.xyape.tite 3(3CaO·P~ ) and CaO X-ray cw 49 

Oxyapatite Ca2P207 and CaO reheated X-ray cw 49 

at 600° 

Oxyapatite ignition Hydroxylapatite or bone 900° x-ray HJM 32 

Fluor-oxyapatite fusion Ca4P209 and deficiency of water 1400° X-ray BFF 33 \Jl 

Other oxyapatites 

3CasP~e • Ba.O Cas(P04)2 and BaO dried at 950° x-:ra.y . BD 49 

3CasP20e·SrO Cae(P04)2 ·and SrO dried at 950° X-ray B:O 49 

3CS.SP20e·Ni0 cae(Po4)2 and NiO dried a.t 950° X-ray B:P 49 

)CasP20e PbO Cas ( P04 ) 2 and PbO dried at 950° x-ray BD 49 )• 

Fluora;eatites 

Wet methods 

Fluorapatite pJ?tion PO~, Ca(OH) 2 , NaF or HF sols. 25° chem,opt Ka 50 

- Dry metho¢ls 

Ca fluorapatites i 

Fluorapatite f3 Cas(P04)2 and Ca.F2 8o0° X-ray cw 50 
Table 1.--Continued 

eral Method Reagents Time and Checked by Reference 

temp 1n •c 

,:,"'n' 

;·].u, rapatite chlorapatite and Ca.F2 8o0° X-ray cw 50 

_;-·:i_u, rapatite hydroxylapatite and C&F2 8o0° X-ray cw 50 

•lu, ra.patite ~ cas (PO"') 2 and CaF2 500° X-ray cw 49 

'PJ.u~ rapatite a cas(P04)2 and Ca.F2 6ooo X-ra)" cw 49 

~·lu~ r-cb1orapatite CaF2, CaCl2, and Caa(P0..,)2 X-ray cw 49 

Flu, r-chlorapatite eb1orapati te and CaF2 X-ray cw 49 

Cbl.orapatites 

Wet methOds 

3Ca:a P20a•CaCl2 pptiont Na2BP04, CaCl~h NaOH, and H20 chem I4'W 29 ~ 

Dry methods 

Ca chlorapatites .. 

Chl~ ~rapatite ~ cas(P04)2 and CaCl2 8o0° X-ra7 cw 50 

Chl 1rapatite hjdrox,yl&patite and CaCl2 in nitrogen aooo x-ray cw 50 

atmosphere 

Chl' ~rapatite Cas(P04)2 and CaCl2 X-ra7,opt DBK 49 

CbJ., 1rapatite Cae(P04)2 a.nd CaCl2 in nitrogen atmosphere x-ray cw 49 

Cbl.1 trapatite fusion cas (PO") a and C&Cl.a 12oo• ,3 hrs opt p. 47 

Chl >rapatite fusion C&s(P04)2 and CaC12 ll00° chem,opt • 41 

ChJ., ~rapatite fusion CaC1.2 . and &tlhydrous Cas (PO,.) 2 in l4oo0 X-ray- HJM 32 
Table 1.--continued 

fineral Method Reagents Time and Checked by Be:rerence 

tem.P in °E: 

:hlorapati te fusion Cae(P04)2, CaCl.2 opt,chem z 16 

Rare-earth and related chlorapatites 

L3.63~ Sm f'usion SmP04_, dry CaCl2, washed with H~ l.l00° chem. c 25 

:hlorapa.ti te 

L'/o Ce chlorapati te fusion Cas(P04)2, CeP04, CaCl2 1150° opt,chem z 23 

L. 6'/o Ce chlorapati te fusion Cas(P04)2, CeP04 1 and CaCl2 1200° opt,chem z 23 

~'/o Ce chlorapatite fusion Cas (P04)2, CeP04 1 and CaCl2 ll00° opt,chem. z 23 

L3~ Ce chlorapati te fusion C&s(P0.,)2, CeP04, and CaCl2 ll00° opt,chem z 23 

~% "Di" chl.orapatite fusion Cas (P0-11,)~21 "Di "P04, and CaCl2 ll8oo opt,chem z 23 _.. 

5~3% Y chlorapatite fUsion Cas(P04)2, IP04, Ca.Cl2 l.l00° opt,chem. z 23 

]llorapatite (Nat) fusion C&e(P04)2, excess NaC1 opt,chem z 16 

Cr chlorapatites 

) • 38'/o Cr chlorapati te fusion C&s(P04}a, C&Cl2 and CaCr04 ll00° chem,opt M 41 

).8'/o Cr chlorapatite fusion Cas(~4)2, C&Cl2 and CaCr04 lJ.OOo ch•,opt M 41 

L.47% Cr chlorapatite ·fusion Cas(P04)a, CaCl2 and CaCrO.a, ll00° ehem,opt M 41 

5.06'/o Cr chlorapatite fusion Cas(P04)2, CaCl2 and CaCr04 11.00° chem,opt, M 41 

X-ray 

0.06cj, Cr chlorapatite fusion Cae(P04)2, CaC12 and CrP04 1100° chem.,opt M 41 
Tab1e ~.--Continued 

Mineral Method Reagents TU.uA Cheeked by Ref'ereace 

tap if~. •c2.74~ Cr, 0.39~ Na fusion 1 CaCla, C&<s(P04} 2 , and Ba~rO• p.oo• chem,opt M 4-l. 

chl.orapatite I 

I 

3.14~ Cr, ?'f, Na tusion Ce.Cla, Cas (PO,.J a1 and liaaCr04 uoo• ehem,opt M 41 

chlorapatite 

I Fe Chlorapatites 

Fe-C~-apatite fusion Ca-Fe-phosphate, CaCJ.a opt,chea p 47 

Fe-el-apatite fusion Fe phosphate, Ca phosphate, CaCla 2 hours 

45 miD 

opt p 47 

90 min 

' hQUrS 6 houre 

(X) 

Pb chJ.oJ'ap.,titee 

3C&:aPaOe •PbCla C&s(P04)a and PbC1a 4ried at ~· X-ray BD49 

Pb-Cl-apatite fusion Ca phosphate, CaCla, Fb phospbl,te '-100°, 1 hr chea,opt, p 47 

spec 

Other ·ChloraJatites 

Sr apatite fusion Srs(P04)21 SrCl2, HgCla 1000' . X-ray, ehem, c 50 .. o»t,spec 

3C&sPaOe •BaCla cas (Po.,J 2 and B&Cl.a c1ri.ed at 950 • X-ray Im~ 

. - . 3Ca3P:a08•Mgdla cas (PO") a and JfSC1a arte4 at~· X•ray :BD· 49 

3C&sPaOa•Bidla C&s(P04)a an4 BiCla dried at~._ X,.r&7-- BD-49 " ...... -. -

o.oi~ Mo chlorapatite fusion ca molybdate, ·CaCla1 Ca phosphate spec p 47 ·. 
· Table 1.--Continued 

Mineral Method Reagents Time and Cheeked by Ref'erenee 

temp 1l'1 •c 

CarbOD&te~15t1tes Dry -=e o4s 

Ca carbonate apatites 

Carbonate-apatite a C&s(P04)a and CaCOs 900. X-ray,opt DBJI 49 ·-

Carbonate-apatite fusion? C&C03 , Ca ( OH) tab BaHCOs, and ll&eP04 X-ray BFJ' 33 

Carbonate~patite earbonate-a;-pati te produced by BFF 7000-BooO x-ray BFF 33 

reheated in dUute HaCOs 

Carbonate-apatite fusion C&s(P04}2 and Ba2C&{COs)a ll00° opt,ehem E 24 

Carbonate-apatite fusion Cae(PO.,.,)a, C&COs, and l'la~a(COs)a 1150° opt,chem. E 24 \0 

Carbonate-apatite fusion cas(PO .. )a, cacos ll.90° opt,ehem E 24 

l3a carbonate apa.ti tes 

3C&sPa0e • :BaCOs cae{ro..,)2 and BaCOs dried at 950°· x-ray BD 49 

Ba-carbonate~patite fusion Ba.COs, Bas {P04) 2 1 and NaaCOs 1050° opt,chem. E 24 

Sr carbonate apatites 

3C&sP.a0a•SrCOs Cas(P04}a and SrCOs dried at 950° X-ray- BD 49 

Sr-earbonate-apatite fusion SrCOs, Sr3 (P04)2, and Ba2COs l04o0 opt,eheJa E 24 

other carbonate~patites 

3C&sPa0a • PbCOs Cas(PO .. Ja and PbC03 dried at 950 ° x-ray BD 49 

---

30asPaOa•ZnCOs Ca3 (P04)a and ZnCOs dried at 950° :X:-ra,- BD 49 
Tab1e 1.--Continued 

Mineral Method Reagents Time and Checked by Re:terenae· temp in °C 

other apatites 

3C&.,P~e • Ca.P2 cas(P04)a and CaPa dried at 950° X-ray BDlt-9 

.Al-apatite fusion Al-phosphate, cas(Po.)a, CaCla 1.100°, 1 hr chea,opt p 47 

Ellestadi te sintering Ca silicate, CaS04: and CaF2 1100° X-ray ID 42 

Hydl·oxyl-ellestadite ellestadi te and steam uooo X-ray ID42 

Ca1oSiP4SOa.:Fa same as ellestadite 1100° x-ray ID 42 

Ca1oSiaPaSaOa.ra same as ellestadi te 1100° X-ray I(]) 42 

HaeCa..SeOa.,P'a fusion Na and Ca sul.tates and CaFa aooo X-ray ID la-2 b 

HaaCaeP4SaOa..,P'a made as above 8o0° X-ray ID 42 " ' 

Na_.CaePaS40a.,.Fa made as above 8o0° X-ray XD42 

Hydroxy compounds made b7 treatment w1 th steam of the 1100° X-ray m ~t-2 _ ot above above compounds s,n.thesized by KD 

Ellestadite fusion? X-ray lQ) lt.J. 

Hydraxyl-ellestadite ellestadi te and steam. 1ooo• X-ra;r ID. 41 

Baeca.(so")eFa fUsion? x-ray ID 41 ' ' 

Aluminate-apatite cas(PO ... Ja, cao, AlaOs X-ray BFF 33 

Cyanim.id-apatite Cas(PO•la and CaCI'a X-rq 

BFF '' 

Ferri-apatite cas(PO")a, cao, and FeaOa :x:-ra:r 

:BF.P '' 
Table 1.--Continued 

Mineral Method Reagents Time and Checked by Reference temp in •c 

Sulf'id.e~apatite fusion C&s (PO.,)a and Cs.S04 in closed. iron bomb 1250° X-ray BFF 33 

of' Ca or Fe 

Disordered afitites 

(apatites With 9 or -metal ions) 

Dry methods 

Ca10 • 8S1PsOa<&Fa tu.sion uoo•, 7 hrs x-ray KD 42 

Cas . sPsSOa.,Fa fusion uoo•, 7 hrs x-ray KD 42 

C&1o sSiaPsSOa4Fa :fUsion uoo•, 7 hrs x-ray lCD 42 

• 

Cas. 5SiPsSaOa4Fa fusion 11oo•, 7 hrs x-ray KD 42 

Na2CaeSiP.,S04,Fa tu.sion 1250•, 6 hrs X-ray KD 42 ~ 

Hydrated tri-Me++-eosEhates 

Wet methO ·. 

Tricalcium phosphates -

(3CaO•PaOs)•DHaO pption Ja2HPO• and CaCl2 in amaoniated •dium X-ray cw 49 

(3caO·P~~) ·0-.5Ha0 Above product heated 6oo• x-ray cw 49 

Metastable hydrated pption HsPO.,., Ca(OH) 2 , and water chem.,X-ray ;pH F '7 _tricalcium phosphate 

CasPaOe•0.5HaO pption ca.O, HsP04 , Ca ( OH) 2 , and water 1 miXed slowly 25° chem.,X-ra.,.,pll Ka 37 ... 

cas(P6 .. )a hydrol brushite in water chat SJI 33 ... 

cas(PC>.,)a pption Ca(B03 )a, J&BPO.,, excess of' ammonia chea SH 33 
Table 1.--Continued 

Mineral Method Reagents Time and Checked by Reference ~emp in °C 

Cas(PO.,)a pption O.lN CaHP041 Ca(OH)a sol. chem CB 33 

CasPaOs·nHaO hydrol? ~ or 7 CasPaOe x-ray :BFF 32 

Tricaleium phosphate pption Na3 PO" sol. added slowly to sol. with X-ray HJM 31 

excess C&(NOs)a 

cas(PO.ft)a hydrol C&B4(P04)a·Ha0 and NH.f,OH ehem LTW 29 

Cas(PO.ft)a•HaO pption Na:aHP04 ··l2Ha0, C&Cla, NH40H ~5°-70° chem,X-ray L 35 

C&sP~s pption ehem B 17 

(probably hydrated) 

Tristrontiua and tribarium phosphates 

~ Srs(PO.ft)a SraP207 , SrCOs in stoichiometric proportions 1000° ehem.,X-ray K 39 

Srs(PO.ft)a hydrol SrB4(P04)a•HaO and liR.f,OH ehem LTW 29 

Bas(PO.ft)a pption BaCla, NaaHPO.,, BaOH, and water chem mw 29 

·-
13 

!able 2.--Lattiee eOJlStants of &1Jlthetie apatites 

~ 

lliaeral a e c:• SIMtcitic ~rr&'Yi t:r Ref. 

A A calc. .eas. 

)Qdroxya:patite 

(Saint-GirOD.S)!/ 9.36 6.89 0.7366 BD lt-9 

Hydr'Q%7lapat1 te 

(Holly Sprinss )!/ 9.43 . 6.89 0.73ll BJ) 49 

C&1o(PO.,)s(OH)2 9:4<> 6.93 0.737 K 39 

C&1o(P04)e(Oll)2 9.llo 6.92· • 47 

CasPbs (PO.,)e (OH)2 9.62 7.o8 M 47 

Pbl.o(PO.,)e(OH)2 9-89. 7.28 Jl 47 

Pb1o(PO.,)e(OH)2 9.88 7-32· 0.741 lC 39 

Sr1o(PO.,)s(OH)2 9.74. 7.20 0.739 K 39 

Ba1o(PO.,)e(OH)2 10.19 7-70 . 0.756 K 39 

:5CasP~a • cao 9.474 6.889 0.730 BD 49 

3C&sPa0a•PbO 8.45 6.889 0.729 BD 49 

3CasPaOe • sro 9.45 6.89 0.7295 BD 49 

3CasPaOe ·BaO 9.45 6.89 0.7295 BD 49 

3CasPaOa ·1'10 9.4~ 6.889 0.730 BD 49 

C&1o(P04)eF2 9-36 6.88 0.732 K 41 

1~ Ce chlorapatite 3-165 z 23 

8~ Ce chlorapatite 3·3-3.18 z 23 

3',£"Di"ehlorapatite ;.315- z 23 

3.170 

3.06~ Cr ehlorapatite 9.56 6.73 0.7o4 . 3.22 3.21 M 41 -

3CasPa0a •BaCl2 9.66 6.88 0.7126 BD 49 

!/ Batura! apatite for purposes of comparison 
14 

~able 2.--continued 

Kiaera1 a c c:a 'Specitie. arartt7 •• :r. 

A A calc • .... 3CaaP~a·PbCla 9.66 6.88 0.7J.26 :U·lt-9 

3CasP~a •lfgCla 9.62 6.889 0.7].61 D lt-9 I 

3Ca:,Pa0a•B1Cl.2 9.61 6.889 0.7169 BD49 

3C&sP;20a •:BaCOs 9.45 6.91 0.7317 BD 49 

3CaaP;!Oa ·PbCOs 9.43 6.89 0.7311 BDli-9 

3C&sPaoa•SrCoa 9.45 6.90 0.7306 :049 

3CasP~a·ZDCOs 9.470 6.889 0.730 BD 49 

staff'eli te ( S'taftel.)!/ 9-394 6.889 0.1333 BD 49 

3CasPaOa •caP2 9.4o 6.889 0.7329 BD 49 

CaJ.oSiP4S02.,.1'2 9.45 6.96 0.736 3.09 3.1.3 1C) lt-2 

CaJ.o81P4S024(0H)2 9.414- 6.96 0.736 3.o8 3.01 D 42 

Ca1oSisSsOaf,Fa 9-54 6.99 0.7'2 3.00 ,.o6 1:0 42 

Ca1oSisS.SOa.(OR)a 9.54 6.99 0.732 3 .• 00 3.01 ID 42 

lf&eC&frSe02~2 9.11·9 6.87 0.724 2.81 2.81 ID 42 

!la~sP .. Sz024)'2 9.52 6.90 0.725 2.98 2.97 KJ) 42 

Ca10 .sSiPs02-4)'2 9-35 6.79 0.726 3.19 3.2 I]) 42 

C&s.sPsSOa42 9.46 6.91 o.n1 3.05 3.o8 lCD 42 

Ca1 Si~P3SOa4Fa 9.4<> 6.81 9-724 3.23. ,.20 D lt-2 

cae.sSiPsS2Da4f2 9.46 6.91 0.731 3.04 ;.10 lCD 42 

l'a~ag'SiP .&S02..,P2 9-39 6.89 0.734 '.2li- . < 3~J.(f'i"' .... 'Klf\2'' 

!/ Natural apatite tor purposes ot cOJQ&rison 
15 

!rabl.e 3. --optical coastants ~ SyDth.etic apatites 

llillera1 nO.. a ~. .O.a - dxa Ret. 

Chlorapatite 0.005-Q.0056 zl6 

Chl.orapatite 1.667* M 41 

1~ Ce eblorapatite f :.:).005 z 23 

1.6; Ce chlorapatite 

J:=~ z 23 

8~ Ce ehlorapatite 1.6703 z 23 

1.3~ Ce ehlorapatite 1.666- 1.665- z 23 ; 

1.673 1.672 

6.3j Y ehlorapatite 1.669 z 23 

0.~ Cr ehlorapatite 1.668~ 1.666• M 41 

0 .~ Cr chl.orapati te 1.676~ 1.674* M 41 

1.4~ Cr ehlorapatite 1.682* 1.68o~ M 41 

3.06~ Cr chlorapatite 1.710* 1.707* M 41 

2. 74~ Cr, 0.3~ Na chlorapatite 1.693 1.690 M 41 

3.14~ Cr, ?~ Ba ehl.orapatite 1.701 1.698 M 41 

Fe-CJ.-apatite 1.6745- 1.6711- p 47 

1.6738 1.6704 

Pb-C1-apatite 1.6693 p 47 

Mo-cl.-apatite 1.66llo 1.6615 p 47 

Sr apatite 1.658 1.664 C50 

Ca-earbonate-apatite 1.635 1.626 .,.009-: !-010 E 24 

Ba-earbonate-apatite 1.691 1.683 i;; !.oo86 E 24 ;·-. 

Sr-earbonate-apatite 1.644 1.638 ~· :.0065 E 24 

Al. apatite 1.6681. 1.6643 .· ·.oo,a p 47 

a C&:3(P04)2 -...·. 

1.572 DBM 49 .,, 

* Determined by yellow light 
DISCU'SSIOI AID SU~OI'S 

Each. group of scientists concerned vi th the apatite Jlliaerals has 

its O'Wil prob:Lem which it has attem_pted to so:Lve iD its ow.n •Y· The 

soils scientist is mainly interested in the availability of P205 to 

plants; the physiol.ogist, in the prevention of dental. caries, or the 

mechanisa ot various types o:f metal poisolliDg; the geol.ogist, in the 

BOde ot formation of phosphorite deposits; the Chemist, in eqailibriua 

studies and analytical methods; and the mineralogist, in the crystal 

chemistry o:f the entire group. Yet all. these workers have ~n.:e~untered 

the same probl.ems. 

The prob:Lem of carbonate-apatite, under as yet unresol.ved discussion, is espeeiaJ.l.y interesting to the physiologist,b'~ mineral. 

•tter ot bone is 1tno1m. to bel.ong to the a}8tite group and contains 

some C02 • Carbonate-apatite apparentl.y does not precipitate in aqueous 

systems. Eitel. (1924) el.aims to have crystallized carbonate-apatite 

from a melt, but he determined C02 only qualitativel.y and on a sample 

that may have been impure. lfhe structure of carbonate-apatite is not 

known. 

Hydroxylapatite is very diff'icul.t to dehydrate, even at high 

temperatures. As a consequence of this, many workers have mistaken 

1 t for oocyapatite. ~ structure of oxyapati te is not kno'Wll and_ is 

difiicul.t to visualize. 

'.rrieal.ciwa phosphate, whose existence is questioned by some chellists, 

gives an apatite group X-ray diffraction pattern and is eal.l.ed hydroapatite by some workers. It tends to precipitate as a gel. and -.ay 

absorb _en.9Ugh exce~s CaO to g1 ve the CaO: P~s ratio of apatite OD. 
17 

cheaieal a.nalysis. Dallewgne, Brasseur, ancl Melon (see D.BJI 49) claim 

that it can be distinguishecl froa h1droJt7lapatite··oDly by optical •thoas. 

Previous workers in the field ot apatite syathesis too otten have 

used on1y one or two methods to check the product ot their synthesis. 

Unl.ess optical. methods are ·used, one 1IBD • s apatite -.a7 be au.other Bl8ll 's 

triea1eiua phosphate; unless air is rigidl.y excluded troa the system 

and water is driven ott at a very high temperature, hydroxylapatite will 

be mistaken for oxyapati te. The product of any synthesis sho~d be 

checked. eheaieally, as well as by X-ray and minera1ogic methods. 

In addition to the.problems mentioned above, there are .~7 others 

waiting to be solved by a comprehensive program of apatite s,nthesis, 

such as, the effects of other ions on the stability field of hydroxylapatite; the mechanisms of absorption· by and hydrolysis of precipitated 

basic phosphates; the mode of occurrence of rare elements associated 

with phosphorites. 

Elements and radieal.s that have been substituted synthetieal.l.y in 

apatites are: Ba, Pb, Mg, Ni, Sr, Zn, OH, F, Cl, COs, O, S, CB, Al, Fe, 

Si, Sm, Ba, S04, cr+3, er+6, Ce, "Di", and Y. Elements tbat bave be_en 

observed spectrographically in natural. phosphorites, though they are 

not necessarily present in the apatite structure, are: Pb, cu, Fe, Cr, 

Ti, Mn, Mg, 81 1 Na, K, Li, As, Sn, Zn, Cd, Sb, V, Zr, Sr, Mo, Rb, Au, 

Ga, pt, Pd, TJ., Ta, Ba, Ce, and other rare earths. 

Synthesis of apatite may be usefUl in solving the problems eonnected vi th the apatite group, and may be approached in these various ways: 
18 

1 o Determination o:f the conditions o:f precipitation and 

stability o:f phosphorites, not only in the simple system Ca0-P2 0s-H2D, 

but also in quaternary systems, the :fourth component o:f which would 

be some element normally present in ground water or sea water, such 

as F, Cl, Na, Al, to name only a :few o:f the many possibilities. 

2. Theoretical and experimental studies o:f the possible 

substitutions in the apatite lattice. Many o:f th~ possibilities are 

already known; some are only imperfectly known; and many have not 

been tried. 

3. Study o:f the effects o:f alteration on phosphorites, 

especially with respect to adsorption o:f ions not nortnally·present 

in the lattice in large amountso 

4. Synthesis of pure end members o:f the various isomorphous 

series as standards :for the opticaly and X-ray identification o:f 

natural apatites. 

In order to avoid the difficulties encountered by previous 

authors the :following procedure is tentatively suggested: 

1. Synthesis by dry methods of the desired apatites: the 

products should be checked chemically, optically, by X-ray, differential 

thermal analysis, electron microscopy, and electron diffraction. 

2. Synthesis by wet methods o:f apatites corresponding to those 

made by dry methods: if necessary, the speed of crystallization may be 

increased by seeding with the corresponding apatite made by the dry 

methods. The product again should be completely checked. 
19 

Clarke, Frailk. Wigglesworth, The data. of .eoeheaistry~ Phosphates, 

Apatite: U. s. Geol. Survey Bull. 770, pp. 357-358, 1924 - quoted 

directly. 

!he first synthesis of apatite was effected by A. Daubree, 8 who 

obtained it in crystals by passing the vapor of phosphorus tricbl.oride 

over red-hot 1iae. N. s. Manross7 :f"!l.Sed sodium phosphate either with 

calei1111l chloride, calcium. fluoride, or both together, and so obtained 

chlorapatite, f'l.uorapatite, or a mixture of the two, resembliDg natural 

apatite, at will.· This process, slightl.y modified, "WaS aJ.so a4optecl by 

H. Briegleb8 sueeesstully. G. Forcbbawer9 prepared ehlorapa.ti te by 

fUsing calci'Uil phosphate with sort.iU'Rl chl.oride. When. bone ash or marl 

'W&S used illstead of the artificial calcium phosphate 1 a mixed apatite was 

formed. Similar· resul.ts were reported by Deville and Caron, 1 who h.sed 

bone ash w:1. th a.mm.onium chl.oride and either calcium chloride or fluoride, 

and also by A. Di tte, 2 who repeated ForebbaJIIII!ler 's experillent. By heating calcium phosphate vi th calcium ehl.oride and water, under pressure, 

at 250•, H. Debra,S prepared cblorapatite. E. Weinschenk" also produced 

it by heating cal.ei'WD. chloride, a.lJDROilium phosphate, and amaonium chl.orid.e 

at temperatures of 150° to l8o0 in a sealed tube. F. K. Cameron and 

w. J. MeCaughe,S prepared fluorapatite by dissolving calcium fluoride 

in fused disodium phosphate and liXiviating the coo~ed melt. Chlorapatite 

was formed when diealcium phosphate was added in eo..xcess to molten calcilDl 

ch1oride. When precipitated calcium phospbate was used, eblorspodiosite 

was obtained, Cas(P04 ) 2 ·CaC12 • R. Backen, 8 by tu.sing calcium fluoride 

or eh1oride with calcium phosphate, obtained both species of apatite, and 

also mixed crystals. A~ti te has been reported as present in lead-tu.rnaee 

slags by W. M. Hutchins and J. H. L. Vogt. 8 ~e composition of these 

slag products, however, seems not to have been verified by analysis. 

> '\t.~~-~1· . Footnotes (p. 35 ': ) 

6. Compt. Rend. , vol.. 32, 1.851, p. 625 .. . 7. Liebig's J~en, vol. 82, 1852, p. 353· 

8. Idem, vol.. 97, 1856, p. 95 

9. Idem, vol. 90, 1854, pp. 77, 322. 

Yoathd€es"'~~~6 -358) 

~. Coapt. Rend., vol. 47, 1.858, p. 985. 

2. Idem., vo1. 94, 1.882, p. 1592. 

3. Com:pt. Rend., vol.. 52, 1.861, p. 44. 

4. Zei tsellr ... IC:ryst.. Min. , vol.. 17, 1.890, :P.. 489. 

5. Jour. Phys. Chem., vol.. 15, i9ll., p. 464. 

6. Centralbl. Min., Geol. u. Pal., 1912, p. ·545. 

obtained by J. R. Mourelo ( Chem.. Abst. , vol.. 

from Rev. gen. sci., vol. 26, 191.5, p. 394) • 

7. Iature, vol. 36, 1887, p. 46o. 

8. MineralbUd:tm.g in ·Sehaelzma.ssen, p .. 263. 

Similar results were 

9, 1915, p. 2749; 
l9a 

Arnold, P. W o, The nature of precipitated e&l.cium phosphates: Faraday 

Soc. Transo 336, volo 46, part 12, pp. 1061-1072, l950o 

Solutions of HsP04 or CaHP04 were treated with Ca(OH)2 solutions 

under C02 -:free conditions, and the liquids analyzed for Ca and P after 

a weeka From mixtures with the same initial Ca~P ratios, different 

precipitates were formed depending on the absolute concentrations of 

the initial solutions~ precipitates corresponded to hydroxylapatite, 

more concentrated solutions. (This suggests that equilibrium condi tiona may not always have been attained in one week. E. B o J.) 

Hydroxylapatite vas prepared by simultaneous addition of calcium 

acetate and ammonium phosphate to C02 -f'ree ammonium acetate; the 

mixing continued over 8 br o The solid was left in contact with the 

solution for 2 days, and chemical analysis showed it to have a Ca:P 

atomic ratio equal to lo66. A dehydration curve of this material 

flattens out between 750°C and 1230°Ca Weight loss of 2.07 percent 

between 1230°C and 14o0°C is ascribed to the·break up of hydroxyl 

groups in the latticeo Octoca.lcium phosphate, Ca~(P04)3, was made 

by adding CaC12 to NaHP04 solution; precipitates equilibrated for 

a longer time had a higher Ca:P ratio than the formula requires. 

Gelatinous precipitates were prepared by rapid mixing of Ca( OH) 2 and 

HsP04 solutions and separated by centrifuging; some of these precipitates were examined by X-ray diffraction. Materials more basic 

than hydroxylapatite were prepared in this way o X -ray diffraction 
19b 

patterns of the materials with the Ca:P ratio of octoclacium phosphate 

were similar to those of hydroxylapatite with the strongest brushite 

lines; additional lines (d = 2.31, t·66o, 5~86, 9.33, ll, and 22 A) . ~~ 

present in one pattern, and one line at 9.34 A in another pattern, 

are supposed by the author to correspond to a possible sheet structure 

of octocalcium phosphate. The solids more basic than hydroxylapatite 

gave diffuse lines corresponding to an apatite pattern. A structure 

for octocalcium phosphate is suggested in which "column" calciums 

(as opposed to"hexagonal screw" calciums) and F and OEI. ions of the 

apatite sctructure are omitted, and calcium phosphate sheets are 

bound in pairs by hydrogen and calcium ions; water molecules bind 

these sheet pairs to each other. Calcium added to this structure 

would replace the hydrogen bi~~ the sheets: this could account 

for the complete range of compositions from Ca:P = lo33 to 

Ca:P - 1.67. Solids more ··bade than hydroxylapatite may be accounted 

for by the large specific surface of these precipitates. Column 

calciums may be exposed on the surfaceo Thus in a poorly crystalline, 

fine-grained precipitate, where the surface is large, the Ca:P ratio 

will be highero This large specific surface may also account for the 

excess hydroxyl and fluorine found in many phosphate rocks. Exposed 

column calciums may produce a surface with a charge which could be 

compensated by an ionically bound layer of F or OK ions. 
20 

B 17 - Bassett, H., ft.e systea cao-P~-H~ at 25•: Chea. Soc. LonG.on Jour. 

III, pp. 620-611.2, 1917. 

In the basic part of the system CaO-PaOs-llaO, two COQOUU~ are 

precipitated: C&sP~8 and 3(C&sPa08 )·C&(OH)2• Bassett calls the 

apatite phase oxyapatite, al:though he gives it the foraul.a. ot hydroxylapatite,; in order to make up analytical deficiency,· he must assuae that 

llater is present' "so firmly held that it eoul.d not be driven oft even 

b7 very strong ignition." Quick mixiDg of l.iquid reagents and consequent 

gel. formation led to great difficulty iD. attainiDg equil.ibrilDR, even 

after one and a half years. Because :Bassett used solid reagents, which 

are metastable, his equilibri'Ulll data do not agree with Kazakov (see K 

37). C02 is not al.ways successfUlly excluded from the system: 0.5 to 

1. 0 percent C02 is present in both solid phases. Some of the oxyapati te 

obtained vas pinkish; qualitative tests shovel the presence of traces of 

Cu. :Bassett fill8J.ly suggests that the apatite pbase might be hydroxylapatite. 

BD 49 

Brasseur, Henri A. L., and Da.llemagne, Mareel J., La synt~se des apatites: 

Soc. chim. France Bull., fase. 3-4, mars-avril pp. 135-137, 1949. 

CasP~8 and chl.orides, fl.uorides, oxides, earbOD&tes, and sulfates 

of' various metals were mixed (wet) in stoichiometric proportions and 

the mixture oven-dried at 900-950°C. for several hours; the products 

were studied by the Bra.gg-Brentano ( ? ) powder method. The discussion 

of synthetic apatites includes a listing of c: a ratios calculated from 

powder patterns (see below). All of the oxyapatites have similar e and 
2l 

a axes; those of Pb and Ba have slightly larger ones; intensity variations 

for the same lines are im.percep:t;ible. C&rbonate•apati tes have a larser 

e:a ratio than oxyapatites. !he c axes of cblorapatites aad oxyapatites 

are equal; the a axis is larger in. ehlorapati tee than in ox,apati tes. 

SUl.fapati tee were not successtul.ly synthesized. In the carboute-apati te 

SJ,Btheses, the crucible containing the tricalcium phosphate was placed 

in a closed crucible containing the carbonate. Hendricks, Jefferso:a 

and Moosley (sic) are quoted as saying that larger ions substitutiD.g for 

F are placed half way along c between F positions, coordinated vi th 6 

instead of 3 Ca. 

Apatite a in kx cinkx c:a 

3CasP~a·BaC12 9.64 6.87 0 .• 7126 

3CasP~a·PbC12 9.64 6.87 0.7126 

3CasPaOe •MgCl2 9.6o 6.875 0.7161 

3CasP~a·BiCl2 9.59 6.875 0.7169 

3C&sP2Pe • PbO 8.43 1>.875 0."729 

3CasP~a·sra 9.43 6.88 0.7295 

3CasPa.Oe ·BaO 9.43 6.88 0.7295 

3C&sP:aOa •cao 9.455 6.875 0.730 

3CasP~a·lli0 9.415. 6.875 0.730 

3C&GPaOe•ZnCOs 9.451 6.875 0.730 

3CasPaOe•SrCOs 9.43 6.89 0.7306 

3CasP:a<>a·PbCOs 9.41 6.88 0.7311 

3CasPaOa •BaCOs 9.43 6.90 0.7317 
22 

Apatite a iB let e in let c:a 

3CasP2!Je ·C&P2 9.38 6.875 o. 7329 

Os Gabrie1•C&Cl2 (sic) 9.61 6.875 0.7154 

HydrQ%7lapatite 9.41 6.88 0.7311 

(Bolly Springs) 

Staff' elite ( Sta.ttel) 9.375 6.875 0.7333 

H,-droxylapati te 9-34 6.88 0.7366 

( Saillt-Girons) 

BPF•32 

Bredig, M. A., Franek, H. H., and Fuldner, H., Beitrage zur KenntDis 

der Kal.lt-Phosphorslure-VerbiDdUDgen: Zeitschr. nelttrochem.ie 38, 

p. 158, 1932. 

This paper presents data on the system C&O·P~s. !l!bree different 

forms of CasPaOe were found; the alpha form. is stable :f.'rODl 6ooo-Boo•c. 

and gives an apatite pattern; the beta fora is stable from. Boo 0 to 

uao· j the gamma form is stable from uao· to the melting point at 

1500°. Beta and gaama f'orms can invert to the alpha form ODl.y by 

heating in water. The mechanism of this inversion is either the formation of a hydrate (C&sP~ ·nHaO) or, by hydrolysis, a hydroxylapatite. 

On heating w1 th an excess of' cao, the alpha pattern persists to hip 

temperatures, because of the formation of oxyapatite. cao iJ1 excess 

of that demanded by the apatite f'oraul.a ean enter into the apatite 

lattice at higher temperatures; the C&O/CasP;!Ja ratio rises to 2:3 

at 1350•, and can be alm.ost as high as 1:1. Excess Ce.F2 up to 35 :mol 

percent ean also enter into the apatite lattice. Because the present 

writers have found enough excess ca to satisfy this excess F, they 
23 

obJect to the h.Jpothesis of Hendricks, Hill, Jacob, and Jefferson 

(see BBJJ 31) that this excess F is coordiDated vi th P, substi tuti:os 

tor o. Heatirlg C&s(P04 ) 2 with less than enough cao to fora ox,apatite 

gave a llixture of a + fS or 7 Ce.sP~ , bat no mix-crystals. Reatinl 

C&sP~a with 20 11.01 percent CaO tor 120 hours at 1ooo•c. produced a 

Jllixture of BlCh ~ C&sP~s 1 but little of the a form.; heating the same 

airtu.re at 1ooo•c. for 500 hours gave a mixture of little of the beta 

fora, much of the alpha form.. The authors explain this apparent anOMJ.y 

b7 the relative rapidity of the reactions ot water los.s and the entry 

ot cao into the lattice to form apatite. 0%7apatite, heated at about 

1oo•c. below its meltiDg point, dissociates to a Jdxture of 7 Cas(P04)2 

and Ca..,P~g. !rhere is a eutectic point at 1325°C. ·for 1 cas(P04J2 and 

Ca..,P~e· At 1550•c. CaO and C8.4P~e form., their proportioJtS depending 

on the e011position of the miXture. C8.4P~e is prevented from tormins 

by 2 percent CaF2 ; when this is present, the apatite pattern persists 

at high tem;peratures, because of the formation of oxy-- and tluorapati tes. 

Criticism following paper: 1 t is actually a phase die~aa of the 

ternary system lime-phosphate-water, as partial presam:-e of water vapor 

at rOOJD. temperature and pressure is enough to form., not oxy-, but hydrOXJ'l.-

apatite. In a water-tree system, 7 tricalcium phosphate and tetracalcilDI 

phosphate llligbt form at l.owr temperatures o 
BJ'J' 33 

Bredig, M. A., Franek, H. H., Fuldner, H., Beitrage zw Kermtnis der 

Kalk-Phosphorsllure Verbindlmgen: Zeitsehr. neld;rocheaie, 39, p. 

959, 1933. 

I. Structural chemistry of the apatite group 

a) Phase diagram of the water-tree s)'Stem C&O·C&sPaOs--Apa.tite 

occurs only in the field previously ocC\lpied. b1' 7 C&s(P04)2; ~P~e 

appears throughout at 50 mol percent cao; 7 C&s(P0..,)2 does not appear. 

b) Powder patterns are given for hytlroxyl-o:q- and fluor-OX18-patites 

synthesized by beating with less than stoichiometric water; these mel~ 

to either Ca..,P,209 or ~~9 + CaF2 above 14oo•c. 

e) Precipitated tricalcium phosphate contains excess adsorbed P~ • 

d) Other apatites with bivalent radicals 

1) The natu:ra.l carbonate-apatites are usually 11.0re. tinegrained tban apatites with less or no earboDate content. carbonate 

apatite was synthesized by these authors :from C&COs + c8.(0li)2 + lldCOs + 

HasP04 heated for a long time. ~e product gave an apatite pattern; 

crystal size was ilrlproved by heating at 700-8oo°C. in weak R~Os. 

2) Sul.fate- and sul.fide-apati te were produced by heatiD.g 

Cas(P04)2 + CaS04 in a slDBl.l el.osed iron bomb (reducing condition). 

It is not yet known 'Whether this is a Ca or an Fe sul.fide-apati te. 

3) Cyanimidapa.tite was produced by heatiDg together Cas(P0..,)2 + 

CaCN2. ~e authors suggest that N is in the F position. 

4) Al:wninate- and terri-apatite were produced by heatiD.g 

Cas (P04 )2 + CaO and Fe~3 or Al:t.ls. The authors suggest here the 

general formul.a: 
Ca1o(P04)eX211Yn where X is OB,P,Cl; :m and n_are equal to one, Y is R''• 

II. ~ reversible inversion of' triealciua phosphate froa the beta to 

the alpha. form. is affected b7 the presence of' excess CaO aDd •ter (also 

perhaps by Cal'2, C&Cla, or even C&CI2). 

Belopol.' sldi, A. P., !'aperova, A. A., SerebreJUliltova, M. ~., Sh:aJ.. 'giD&, 

M. B., Physicochemical anaJ.ysis in the f'ield of sul.furie acid. treat-

-.ent of' pho$phates: I. ft.e ternary systea calcium. oxide-phosphorus 

pentoxide-water at 8o0 : Jour. Chem. Ind.·. URSS, vol. 14, pp. 5()4-

507, 1937. 

nis paper deals v:l.th the s7Stea betveen 0.13 8.Jld 48.9 percent 

P~, aD.d gives equilibril1Dl data tor Ca(H~ • Therefore its subJect · 

•tter is not germane to the present collection of' abstracts. 

C&robbi, G., Rieherche sul.le relazioni d' isoaorfism.o :rra i composti del 

s-.rio e quelli corrispoadenti del ealcio, dello stronzio, del. bario, 

e del. piombo: R. acead. Napoli Fis. Kat., pp. 83-95, 1925. 

The COJQOUllds Sm.Cl2 and Smi2 are known, where Sm is divalent; 

~onini has ia"'estigated substitutions o:f' the rare earths f'or the 

alkaline earths, and the rol.e ot samarilDl is here investigated :rurther. 

Com;pounds s,athesized in this stuey are: 

~(MoO" )s and 8112(MoO.c, )s •15ll;a0 

Mix ·crystals from ~ SB2(Ko04)3 -lOj, PbMo04 to. 1~ ~(Ko0-&)sCJC11, PbMo04 (9 experiments) • 

ll1x et)Stals up to a -.xiaua of. 68.8~ Sllta(~)s-31..~ Cd884r 

( 4 aperiMnts) • 
26 

Mix crystals of 1&6.56;. Sma(JioO.-)s-53.44; SrJio04 (1 experiJaent) 

SmP04 • 2HaO . vas prepared troa hot and cold solutions of S.(IOs )a 

and B&sP04. 

Samarif'erous chlorapati te was prepared by fusing for 3 hoUrs at 

ll00°C. a mixture of 0.5126 g SmP04·, 3 g Ce.s(PO.~Ja, and 6 g C&Cl2. !he 

product of this fusion was washed with water. Very s-.ll. crystals; with 

(loio) and (lOll) taees were obtained. ~ey were uniaxial (-), clear 

and colorless, and bad weak birefringence; they contained 13.63~ SJBP04, 

equivalent to 9 o67jJ SmaOs· According to the results of all these syntheses 

it should be possible to synthesize apatites containing even more samarium. 

Carobbi, Guido, Celestina e apatite di stronzio contenenti piceole 

qua.n.tita di mercurio: Accad. Bazionale dei Lincei Atti, series 8, 

vol. 8, fasc. 2, pp. 87-93, 1950. 

Kercury is widely diffused in nature, generally in the order of 

10-8 grams per 100 grams. Trace elements in such minerals as sphalerite 

and apatite are a guide to their conditions of formation and genesis. 

ne ionic radii of di val.ent mercury and strontium. are similar, indicatiDg 

the possibilit7 of mu~ substitution; mercury is known to occur in . ·~· . 

DQ.tural strontian celestite. and apatite ill the order of. 1 x lo-4 to 

17 x lo-4 percent, and in natural and s,nthetic barite. 

Celestite was s;ynthesized by adding l.5 ec of concentrated li2 SO.- aud 

100 ee of SrC12 sol.ution ( 4o g per 11 ter) to 100 ee of a concentrated 

solution of HgC12 • ft.e precipitate 'Was left in eon tact with the liquid 

tor some days, fil~ered, and 'Washed with dilute RaS04. ~e crystals 
27 

were rhombic, about o.o~-. in size, ancl were both tabular aad prisDI&tie 

in habit, with re:rraetive illcliees nX = 1..620, nY = 1.622, BZ = 1.629. 

Mercury was utermined by the dithizone Mthod: the crystals were tissolved in KaCOs and DOs, and neutralized with ~RtrOH; a 0 .005-percent 

sol.ution of dithizone in CCJ..., was added, and the resulting so~utiOJl was 

titrated against a similar solation of pure dithizone by adding Hg(BOs)z. 

The obtained result of 0.002 percent Rg •s cheeked spectrographicall7 

by electrol.yzing the sol.ution a.ud checking the liaes obtained OD intermittent sparking against Mg lines. Under the microscope the erystal.s 

were not hoti.Ogeneous, but had very sJDall. inclusions of higher index. 

Two other syntheses were atteQted by similar methods using HgS04 

treated with HNOs to oxidize al.l the mercury. Although. X-ray diffraction 

patterns showed nothing but celestite l.ines in the precipitate, microscopic examination showed that the crystals were not homogeneous. 

Strontian apatite was crystallized from a mixture of Srs(P04)2, 

SrCl2, and HgCl2 fUsed at 1000°C.; the cry-stals were washed with vater 

and acetic acid. Hg escaped and sublimated during the f\lsion, but the 

crystals still contained 0 .001 percent Hg. !ale erysta1s were mostl.y 

tabalar, but a f'ew were el.onpted along the ~ism; the prismatic crystals 

-were 0.01 mra l.ong, the tabular crystals, 0.05 mm in diameter. ~ey had 

re:rractive indices nO = 1.658, nE = 1..664. Microscopic examination 

showed that no miX-crystals bad been obtained, but that the crystals 

contained small. diffused inclusions of higher refractive index. 
28 

' / , Clarens, J., aacl Brlmeton, M., Contribution a 1 'etude des reactions 

JIUtuelles des phospbates et des sols J prelli~ note: action de la 

chaux sur le phosphate aonocalcique: Soc. ehim. :France Bull.. 53, 

pp. 1.431-1435, 1933. 

The authors mixed solutions 0.1 lJ in C&BPO.t. with sol.utions of 

ca.( OR) 2 of various eonee:atrations. ~e sol.utions were ai.Xed rapidl.y, 

either at rooa tem;perature or interm.1:ttentl.y heated over steaa. After 

precipitation, the solutions were ual.yzed for HsP04 by titration w::Lth 

uranyl nitrate. !fhe solid products are interpreted from the COli;POSi• 

tion of the sol.utions to be mono- and triealeiua phosphates. 

Clark, N. A., The system Ca0-P;a0 -H~: Jour. Physical Chemistry, vol. 

35' pp. 1232-1238, 1931. 

~is paper gives equillbrium data for aono- and di-ealciua phosphate. The •terial presented here has no direct bearing on the s,athesis 

ot apatite. 

Cbaudroa, G., and Wal.lae,.s, R., Sy.nthese ' des apatites par reaction / dans 

1 'etat sol.ide: Soe. ehim. France Bull. tasc. 3-4, mrs-avril, pp. 

132-134' 1949. 

The authors prepared a C&s(P04 ) 2 (uncertain hydration) by reaction 

of :la~o., and C&Cl.2 in an uaoniated m.ediua. This COJIIPOUD.d loses water 

gradually to 6oo•c., 'Where olll.y 0.5 molecules of vater re-.in for 3 

· mol.eeul.es of' the &.Dhydrous phosphate. ~is last water is rapill.y lost 

on further heating, and the phospbate inverts to the beta :tora. At 
temperatures above 1200 •c., the phosphate inverts to the g&11l8 tora, 

and eaa be turned back to the 'beta torm. b7 heating at 6oo-Boo•c. 

a Ce.s(PO.eJ2 has a structure not f'ar removed from that ot apatite; it 

does not give a good X-ray diff'raction pattern unless it is heated at 

4oo•c. as it is very poorly crystallized. Preparation of apatites: 

. 1) Fluorapatite was -.a.e f'roa a dey' llixture ot a cas(P0,.)2 and 

C&F2 heated above 6oo •; differential thermal curves of this reaction 

show a rapid but progressive vater loss; the authors therefore postulate the substitution of F for Ol:I. Fluorapatite •s also produced b7 

vrt:x::hag dry ~ C&s(P04 ) 2 with Ca.F2 : this reaction takes place abru.ptl.y 

at 500•c. 

2) Rydr0X7l- and ox,apatite were produced by satl11"&ting BsP04 

with Ca(OR)2 at 1oo•c. A mixture of J3 C&s(P04 ) 2 and cao (dry) reacted 

incOJIPlete~y, resulting in a mixture of p Ce.s(:P04 ) 2 and &:;?atite. Fusion 

of Ca2P~ and CaO iD. oxyapati te proportioDS resulted in an tm.stabl.e 

phase, which, reheated at 6oo•c., gave a good oxyapatite diagram. 

(If' air was not excluded, this is probably h:yd:.:-oxyla.patite. EBJ) 

3) Chlorapatite was produced by heatiDg Ce.s(PO.tJ2 and CaCl2 iD. 

a nitrogen atmosphere. If these compounds are miXed 'Wet or in air, 

their product gives a pattern which may indicate partial substitution 

of Cl for C&O; the powder pattern is then between those of oxyapatite 

&lld ehl.orapati te. 

4) Mixed ehlor-f'luor.o.apati tes were produced either by action of 

C&Fa on ehlorapa.tite, or by heating a mixture of C&F2, C&Cl2, and C&s{PO.)a. 

These mixed apatites prove that there is a continuous isomorphous series 

between chl.or- and tluorapatites. 
Chaudron, Georges, and Wallaeys, Robert, Etude de la substitution, daas 

l'hyiiroxyapatite, du radical hydroxy-le par le eblor ou le t1uor, et 

dans l.a chJ.orapatite, du cbl.cre par le f'l.uor: ~~·~.rsc::t~~~i.s:V~Qmptes 

~<}.US,)l~f\roJ: •. ~.2~0j.,·~~ .. 2l, May 1950. 

Chl.orapa.tite and fluorapatite were prepared by adding ca.F2 or Ce.Cl2 

to anhydrous triealciUll phosphate at a"b011t Boo °C. Hydroxylapatite was 

prepared by saturating phosphoric acid with milk of 1ime at l00°C., and 

heating the precipitate at ll00°C. to elimiDate adsorbed 'Water. All 

products were cheeked by X-ray diffraction methods. 

When ehl.orapatite is heated at about 8oo°C. with calcium fluoride, 

its powder pattern changes to that of f'luorape.ti te, and water-soluble 

~eium. eh1oride is set free. When hydroxylapa.ti te is heated at about 

8o0°C. 'With caleium. ebl.oride in a nitrogen f' .. tm.osp!lel·e, the f'ollowiDg 

reaction takes place: 

3(3CaO·P~ )C&(OH) 2 + CaC12~3(3C&O•P~ )CaCla + Ca.O + H:e(l 

A silllilar reaction takes place between hydroXy'lapatite and Ca.F2 to 

form fluorapatite. In the le.tter ease 1 the X-ra.y diffraction patterns 

of fluorapatite and hydroxyla~f)at5.t·.3 are very s:im:iJar but may be distinguished by a dif'f'erence of 0.05 A ill the.! diae!lSion of the unit cell. 

~enal. analysis of' the reaction between h)"droxyla;.ft&'tite a.:J.d CaF2 shows 

that there is a quantitative water loss as the temperature rises above 

6oooc.; hydroxyl.apa.tite heated by 5.tself is stable at ~ratures ~bove 

1000°C. 

The substitutions described above may be partial. as well as e01119lete. 

Uader the eonditions of these experiments, the eODfPOUJlds flBY be arra.nged 

in order of increasing stabUi ty: hydroxylapatite, c:hl.orapati te, fluorapatite. 
31 

Dall.eape, M. J., Brasseur, H., Mel.on, J., La eoutitutiou. cle la substance ainhale de l'os et la s,nth'ese des. apatites: Soe. chia. 

J'ral'lce Bull. f'asc. 3-4, mars-avril P:P• ~38-145, 1949. 

In ·trr.tng to resolve the question of' the llilleral com;position of 

bone, the authors diseuse the reactions between a and f3 C&s(P0.,)2, 

hydroxylapatite, bru.shite, and oxyapatite. !fhey give X-ray powder 

patterns tar a1.1 products. 

1. Boae freed of' organic substances has the sa.ae C02 elilaiatiou eurve 

as lO: 1 aixture of Ce.s (PO.er) 2 and CaCOs. WbtfB most of the CaCOs is 

dissol.ved out of bone, leaving II.OSt of the ~hospbate, the Ca/P ratio is 

1.94, vhich is equal to ~t of cas(F04)2. /Bone alone gives a poor 

I 

potftier patten; ldl.en eal.eined at 900•c., it /gives an apatite pattern; 

this was previously interpreted as improvem+nt of crystallization due ' -

_to heating. 

2. a C&s(P04 ) 2 has two molecules ot -water and gives a pololder pattern 

similar to that of hydroxylapatite. 

C&s(P04)2•H2(0H)2 (a trieal.cium. phosphate) 

Cas(P04)2•C&(OH)2 (hydroxylapatite) 

Wilen a Cas(P04)2 is heated to 700°C., it inverts to the bei;a. fora. ~s 

inversion is distinctive of' a Cas(P04 ) 2 • Bone~ When tt;eated with acid, 

gives au a Cas(P04)2 pattern; after eaJ.eining at 700"C., it gives a 

~ Cas(P04)2 pattern. Apatite (type not speeif'ied-EBJ) treated in this 

._,. 4oes not eha:rlge its pattern. 

3. a Ce.s(P04)2 mixed with CaCOs 966:100 and heated to 900•c. gives &B 

apatite pattern. Thermal. analysis shows that the reaction CO,rP~5 takes 
32 

place within 67o•-89Q•c. Complete dehydration o-r a C&s(P04)2 takes 

place at 7oo•c.; there-rore COs replaces BOll in the alpba lattice. 

!rhe same replacement of this water is possible by Cl, 0, and F, aud 

Mg may replace Ca. The inversion te.perature of C&COs is 884•c. 

Once fixed in the phosphate lattice, C02 cannot be driven ott be1ow 

1050°. 

4. The index of refraction measured with light of 599.1 A (sic) 

using the Becke line method and an Abbe refractometer is used as a 

control. The refractive index of ox-bone mineral. substance is 1.590; 

that of a C&s(P04) 2 is 1.572; the difference is due to 10 percent adsorbed carbonate. Bone calcined at 90o•c. has a refractive index of 1.645; 

the refractive in~x of ~ cas (P04) 2 is J.. 619. 

5. The authors answer objections to their thesis on the basis of 

adsorption of cao by bone in e:xcess of stoiehi0JDL11Jtric proportions; 

this mixture, on heating, produces hydroxylapatite by the followiJJ.g 

reaction: 

3Ca.s(P04)2•H2(0H)2 + eao __,. :;cas(ro4}2·cao + 2H2J (sic). 

The authors maintain that combination of phosphate and lime to fora 

hydroxy-lapatite occurs only at high temperatures. 

The tentative results of another experiment are: 

cac12 + o: cas(P04)2 ~ clllora.pa.tite 

C&Cl2 + hydroxylapatite ~ no change in pattern 

A mixture of brushite and ~ime heated to 900°C. gives either f) C&s(PO.eJ2 

or apatite, depending on the proportions of the miXture. 
"Conel.usiou: 

l.. Tricaleiua· phosphate cloes exist iD the hydrated :rora which. w 

~ve 4escribed, but its pr~tion requires defiaite cpadit.ions. 

Prepared 1Ja. too acid a •diu, 1 t eacl.oses erystal.s of prushi te. 

Prepared. 1D too alkaline a medium., 1 t adsorbs liae. Left in the 

sol.ution b-oa which it -.a prep&recl,· it decomposes. Prepared belinning v:i:th eao, it adsorbs cao, even if it forms iD. a f'iD&ll.y 

neutral aecl.i11111. 

2. ~iealciua phosphate combines with adsorbed lime at 900°C, to 

fora an apatite. 

;. ~s apatite -.y be deeOQosed 'D:y brushite if' the reaction 

proceeds at a high enough taperature. 

4. lleatillg of brushite with lime gives rise to beta trical.eium 

phosphate ar apatite depeD.CliDg on the relative amounts of the reagents." 

E 24 

Eitel, Wilhelll, Uber Karbonatphosphate der Apatitgruppe: Sehr. Konigs- • 

berger Gel.ehrter Gesell. Naturwiss. n, Jahrb. l, Heft 4, pp. 159-

177, 1924. 

A. Caleilllll•carbouate-apatite--3Cae (P04 )2•CaCOs 

I. Investigations in the system Cas (P04 )2--:Na~( COs) 2 

1. 1.000 g Cas(P0..,)2 + 5.5000 g Ifa~a(COs)2 under 31-32 

tg/ cm.2 C02 were heated at 1ooo•c. for 90 lllinutes and cooled very 

slovl.y; the first erystaJJ.ization occurred at 8JI.o •, the second at 

776•, ending at 77o•c. ~ product showed two generations of earboate-
apatite; at the bottom of the melt were stubby prisms of the first 

generat·ion, at the top were thin prisliS eutectically crystallized 

with Jla~a(COs) • ~e crystals of the first generation have a central. 

filling of lla2ca(co3 )2• 

2. 2.000 g cas(PO,.J2 + 3.000 g :ra2ca.(COs)2, under 2~ k.i/ea2 

C021 were held at.l000-l0l0°Co for :;o llliJmtes, and at 1050-106o°C. for 

30 minutes·, to com;p1ete m.el.ti.ng_. A reaction occurred at 755°C.J the 

product was similar to that of (1), but the intergrowth of earbonateapati te and Na2 ca ( C03 ) 2 was poikili tie. 

3. 3.000 g Cas(P04)2 + 2.102 g lfa2Ca(COs)2 under 4<>-43 

kg/cra2 C02 wre heated to 1100° ! 15° for one and a haJ..f hours to 

COJIQ?1ete •J..ting. On cooling (from 1020• to 750•c. in siX and a 

quarter hours) crystalJ.iza.tion occurred at 755-750°C.J the :product 

consisted of long inc1usion-tree crystals of carbonate-apatite in 

a gr01mdass of Na~a(C0 2 crystals. 

II. Invest:t,gations in the ternary system. C&s(P04)a-lla~a(COs)2-

CaC03. 

The first reaction took place at 770a78o•c., the entire mass melted 

at 970°C. ~e melt was held at 1050°Co for 10 minutes, a.nd raised 

briefly to l220°C. under 48 kgjcm2 C02 • Unfortunately, slow cooling 

was 1m.Possib1e. The product consisted o:f skeletal carbonate-apatite 

crystals in a groundmass o:f lia2Ca(OOs)2• 

5. 2.000 g Cas(P04)2 + 2 g CaCOs + 0.505 g Na2ca(COs)2 

on heating showed a first reaction at 820°C.; heating was continued 

to 1150~C. under 54 ks/cm2 C02• ~e product cOD.sisted o:f carbonate-
Figure 19 

Figures 18 and /9 from Eitel, Wilhelm, 1924, P.l69 
liquid / 

/ 

~, 

/ 

,'liquid 

/plus 

j_C,.a!(!_o_~. ·1470• 

/ _, / 0 / (J 

/ a 

1340° / ~ 01 ~ //apatite _ .. ._ 

x\ / o•o , //plus liquid a. !:. 

\ I )( •---;, o_, 

calcite / \ x' x : S u 

plus liquid""' \ 1 &. ., • 

IJ4o• ~--~ X--x--x----, I a_ 

calcite plus · 1 t; 

c • carbonate-apatite IJ :: 

I... a 

.8 II 7 1.0 9 I g g. 1ooo• 1 1ooo• 

CaC01 100.,. Mol % 

Figure 17 

c~o ~ IOOffo 

(Wilhelm Eitel, 1924, P. 168) 

oe-SrC01 plus 

. liquid X-X-)( 930° 

Mol' OJ. Sr C01 

Figure 20 

,./,a -Baco1 plua liquid 

Na2COa )' 810° plus ~x-x-l-X--...;;..;..,;; .... liquid y-BaC01(ps.-hex) plus liquid 

71 )(M X : X . 

Na2 co1-r BaC01 

Mol % 

Figure 20a 

-

Ba C01 

100% 

Figures 17, 20, and 20A from Eifel, Wilhelm, 1924, P. 174-
'' 

apatite an4 calcite, vi~ Ter'7 little kaC&(COs)a. 

6. 1.000 1 Cas(PO.,.)a + 3.003 g C&COs + 1.011 g l'&aCa(COs)a 

under 49 q/J COa 'bepa ae1t1Dg at 76o-77o•, vas held at 850-870• tor 

product •s ai•i 1 ar to that of experiment 5, but bad a great Cleal of 

:pria:ry calcite. 

In. InTestigatioas iD. the system C&s(P0.,.)2-C&COs 

7. 3.000 g C8e (P04) 2 + 3.000 g C&COs were heated to 1152•c •, 

the tem;perature of the eu.tectie. ~ •lt 'W&.S held at this temperature 

tor hal.t an hour, thea raised to 1202•c. 'fb.e pressure was raised froa 

55-0o ks/ca2 C02 to 81 q/ca2 C02 • !he apatite prochtced ha4 inclusions 

of ealci te parallel to the e axis. 

8. 4 g C&COs + 2 g Cee(P04)2 una.er 92 kg/ea2 COa were ·heated 

to 1148-1150 o, then to J.220 •c. On slow coolillg there was a weak "th~ 

effect at 1130°. Again, the central hollows of the apatite erystaJ.s 

parallel to the e axis were fU1ed with calcite. 

9. 6.2 g C&s(P04 ) 2 + 2 g CaCOs under 98-100 kgjem2 COa were 

heated at 1130 o for 4o ainutes and at 1000 •c. for 75 minutes. 'fhe lliXture showed a weak theral. reaction at 114<>•. 'fhe product consisted of 

car'bo•te-apatite crystals iD. a groand-.ss of ealeite. Some of the 

eal.ci te reacted vi th the platin'tlll. 

. 2 

10. 4 g Cas(P04)a + 2 g C&COs under a pressure of 89 kg/ca. 

C02 were heated tO lllK>0 1 then to l215°C. for 20 minutes, &t whiCh 

tempera-ture •1tin.g was still incomplete. !!!he -.ximua pressure was 

97 k8/cul2 C02• !rhe melt was then held at 1050° 'Ullder 8o kgjem.2 for 
50 minutes, and slowly cooled. ~ pro4uct was similar to '"-t of 

ex,peru.nt 91 but eontailled •re calcite. ft.e eal.c1 te again reactecl. 

vi th the platinllll. 

11. 2.5 g Css(P0..,)2 + 3.5 g C&COs, ader 95 qfem2 COa 

were heated to the eutectic tetQer&ture (ll30°) 1 aad o:D. fttrther heatilag 

showed a last weak m.el.ti.Bg at 1170 •c. !!he •xi•111. tem;perature was ll90° 1 

fr011. which the melt •s slowly cooled. ne .~et consisted of 

coarse erystals ot both calcite and carbonate-ape.ti te. ·~ 

ft.e system C&s (PO..,)!~co§-r.:j;rtJ~'i.hi;p~;r.y,~~~J4.::·~i te- ·-~ ...... :-:;~*~·,-t-. ... , .... '• ·"·'- .-_ > 

carbonate-apatite eutectic is at ll4o•c., 3.8 mol percent Cae(P04 ) 2 • 

Carbonate-apatite melts ineo:agruentl.y to Ca3 (P0.,)2 sad liquid. at about 

l.475•c • 

. still tmb.own: 1D.variant points yet to be G.eterained are: 

CaCOs + liquid ~carbonate-apatite + lla~{COs)2 

liquid< .., e&l"bonate-apatite + lia2ca(c<>s)2 + Ba2COs·mix-erystals. 

IV. The physiography (sic) of earb<mate-apati1ie 

The s,nthetic crystals ot carbou.te-apa.ti te were tJ'l)ieally 

long or short prisms w:t th 1.0io 1 l.Oll, aud 0001 faces; the sltel.etal. 

crystals had inclusions along central. canals parallel. to the c axis. 

The refractive indices were found to be: 

Microchemical tests showed the presence o:r C02 • 

~ s,n'thetie c&rb9n&te-apatite is cOmpared to :aatural earboDate• 

apatites from Tonopah, aad the eal.cite-tilled -·skel.etaJ. erystal.s are 

similar to those frOJil the FeDllo-Seandia.n pe~tites. 
37 

B. C&rbouate-apati tea of strontittlll u.d bariua 

laaCOs ad SrCOs tom no double sal.t s1•1Jar t_o IaaCa(Cia)a1 'bltt 

haTe a. eutectic at about 715 •c. SrCOs inverts from "he al.pha to the 

beta tom (th' beta form 18 the high-temperature .fora) at about 92o•c. 

BaCOa u.d l'aaCOs fora no double salt similar to llaaC&(COs)a, aad 

bave a eutectic at about 7o;•c. BaCOs inverts froa the 'beta to the 

~fora at about an•c. (th.e beta fora is the ·high-temperature 

fora). 

a. A mixture of Bas (P04) 2 + :BaCOs + lla~Os in the ao~ecUl.ar 

proportion ot 1:1:2 ws heated under atmospheric pressure for one hour, 

then slowl7 cooled. !he mixture was eoQletel.y -.lted at lo4o•c. ~e 

apatite produced occurred as stUJil!)y prisms with a typical 0001 cleavage, 

D.O.Ia - BIIIa = 0 .oo86, lllCia = l. 683, nOma = 1.691. The crystals had central 

inelusiODs of the carbonate-apatite groundmass. 

b. A mirture of Srs (P04) 2 + SrOOs + liaaC;Os in the moleeular 

propol'tion 1:1:2 •s heated at atmospheric pressure to l.050°C. and held 

there for two hours, then slowly cooled. ~ me~t was dark because of 

the presence of a little tree SrO. The . apa't:15;e had characteristic cleavage· and prismatic habit, with nO = lo644, n1 = lo638, nO-nE = Oo0065. 

JF4o 

Elmore, Kelly L., and Farr, !had D., Equil.ibriwa in the SJ"Stem calcium 

oxide-phosphorus pentoxide-water: Indo and .Eng. Chellistry, Anal. ld. 

32, no. 4, PPo 58o~586, 194o. 

Solubil.~ty and equilibrium data are given for moaoealcium phosphate 

(monohydrate and anhydrous) and diealeium phosphate (dihydrate and ahydrous) • This aaterial has no direct bearing on the s:rnthesis of apa.ti te. 
Eisenberger, Sidney; Lehnlan, Alemnder; 81.4 Turner, Villia D.; !he 

basic calcium phosphates and related 87fJ'M11S. Some theoretical and 

practical aspects: Chea. Rev., vol. 261 ~· 257-296, 194o. 

A review of the literature with 230 references. Jfaterial applicable · 

to the synthesis of apatite is abstracted elsewhere in this paper. 

Part I. CalciUDl phosphate systems 

I. 'fbe binary system CaO-P~5 

II. 'fhe basic region of the system O&O-Pa05 -BaQ 

A. The phase diagram 

B. 'lhe phase diagram for calei'Wl ars$nates 

c. ft.e nature of precipitated basic calcium phosphate 

D. Reaction rates 

Ill. ~e stability of the apatite lattice 

A. Mineralogical studies 

B. Basic phosphates of other metals 

Part II. Practical applications 

I. Phosphatic fertilizers 

A. CaJ.cined phosphate 

B. Thomas meal 

II. The removal of the fluoride ion from water 

III. The inorganic constituents of bone 

A. Carbonate apatite versus hydroxylapatite 

B. Minor constituents 

C. Crystal orientation 

D. Physicochemical considerations 

Conclusion 
39 

J'ouretier, Georges, La pr,cipi tation du phospha-te tricalcique et. l 'h)"droXJ'• 

apatite: ~t-::sci~~al'~('~J)-tes':~~,nli~,205~7:PP· 413-415, 1937. 

Precipitates produced by rapid mixing of !lore or less dilute B'sfO• 

8D4 Ca(OB)2 w'ere studied by chemical 8J'.lal.ysis of the liquid, X-ray of 

I 

the solid, and deteraination of. pH. ~e author theorizes that the observed fluctuation in pH is produced :by metastable tricalcium phosphate 

slowly going over to apatite; he draws a parallel between this and the 

hydrolysis of brushite. 

G44 

- Greenwald, Isidor, Anomalous eff"eets in the titration of' :Phosphoric 

acid with ealeiUlll hydroxi~e: Am. Chem. Soc. Jour. 66, pp. 1305-

13()6, 1944. 

!fhe anomalous effect in question is, that after one equivalent 

Ca(OB)a has been added to a solution of RsP04 , further addition lowers 

the pH.; pH rises upon standing. Previous authors explained this 

effect by the conversion of CaBP04 to Cae(P04 ) 2 ; the present author 

f'inds that this does not explain the return to a higher plt after 

sta.Jlding. 

Greel\wal.d believes that the precipitate is not apatite or Cae(PO_.)a, 

but CaiiP04 and Ca(OH) 2 or a compound having a. Ca:P ra:tio greater than 

1.5. The first precipitate is Ca.HP04 , whieh on standing li ..-.,:,tQ.\._ 

Ca(OH)a•caP04. If a crystal of Ca.s(P04 ) 2 is added, that compound 

crystallizes; otherwise the above metastable precipitate remains. 
4o. 

~ . / 

Rebert, Claude, Contribution ~ l' etude de 1a ehimie des phosphates de 

calcium: Armales des mines Kem. 136, no. 4, pp. 5-93, 1947~ 

I. Qualitative spectrographic analysis of impuritles in natureu phosphates. 

The phosphates were separated into about 1.0 tractions bf iileans of 

' ·. . ' specially purified reagents; the Fery spectrograph was used tbr the 

2500-46oo A region, the Cojan spectrograph for the 3500-68oO A region. 

The following elements were common to natural phosphorites, ox 

bones, and. apatite: Pb, Cu, Fe, Cr, Al, Ti, Mn, Mg, Si, l's., lC) ti, As, 

Sn, Zn. Cd, Sb, V, Zr, Sr were found in natural. phosphorites but not 

in bone. Au, Ga, W, Pt, Pd, Tl, Ta, Ba. were rarely found; Mo was :trequently found. Rb was found in Tennessee, Lorraine, and Nassau phosphorites. Radioactivity was present as shown below; it is expressed as 

mg of equivalent U/g phosphate. 

Morocco 0.203 Carolina. o.82 

Morocco 0.336 Oceania 0.232 

Gafsa 0.23 Lorraine 0.157 

Constantine 0.202 Nassau 0.101 

Constantine 0.262 Nar lu ( Sol'Dme) 0.27 

Kosseir {Egypt) 0.14 Cuesmes (Belg) 0.3 

Kola 0.173 Crystalline apatite 0.37 

. Florida 0.69 FJ.a.t ox bone 0.036 

Tennessee 0.038 Long ox bone 0 .. 029 

!he radioactivity is concentrated especially in fraction IV (precipitate 

of ammoniacal magnesian phosphate from citric acid medium), in fraction 
V (precipitate ot iron sulfide), and in traction I (insoluble in 

hydrochloric acid). 

II. Methods ot measurement, analysis, and preparations. 

Discussion on pH .eas\lrem.ents and on ca1cium sulfite. Ca2H2 (P0..,)2 

anhydride and hydrate were prepared by mixing slightly acid solutions 

ot Ca(OH)2 and HsP04 , acid in slight excess, and agitating f'or 48 hours. 

!rhe hydrate was prepared from cold solutions, the anhydride from boiling solutions; the inversion point is about 8o°C. Ca.l4(P04)2 is stable 

from pH 3.5 to pH 5.0; Ca2H2(P04J2 hydrate, from pH 6.5 to pH 7 .5. 

III. !l'he attack ot strong acids on the calcium phosphates. 

Cas(P04)2 was precipitated from 12 N solutions of Ca(OH)2 and 

· lJsPO• and has one molecule of water. Apatite and· natural phosphates are 

generally less attacked than is Cas (P04 ) a. Acids used here are: oxalic, 

perchloric, nitric, sul~~ie, and hydrochloric. 

IV. file attack of medium acids (phosphoric, acetic, ci trie) on the 

calcium phosphates ie similar, but less marked, than tha.t of strong 

acids. 

V. The attack of weak acids (boric, suJ.:furous) on the calcium phosphates. 

Boric acid has no effect on the calcium phosphates; suJ.:f'urous acid 

attacks them, but the calcium sulfite oxydizes and gives an abnorma:l 

curve. 
BHJJ 31 

Hendricks, s. B., Bill, w •. t., Jacob, E. D., and Jef'f'erson, 11. E., 

Structural eharacteristies of apatite-like sUbstances, and campo-

. sition ot phosphate rock and bone as deteria:l.ned troa microscopic 

and. x-ray diffraction exami natioru lad. and Ens. Chemistry 23, 

no. 12, pp. 1413-1418, Dee. 1931. 

Various minerals have been thought to exist in phosphorites by 

Lacroix, Schaller, Rogers, and othersj the mineral substance of' bone 

has been thought to be either a carbonate-apatite or hydroxyla.pati te 

·with calei te or hydrous tricalcium. phosphate. An ex,planation of 

Rehmel 's and Baray-Szabo • s interpretations of the apatite structure 

follows. Hydrated tricalcium phosphate cb.a11ges to the beta fora by 

heating to constant weight at 9()0°C.; the hydrated f'orm is believed 

to have an apatite structure and to fora a complete solid solution 

with hydroxylapatite;· ~-:Bone- ~fJ :e::t CaO:PaOs ratio greater than 

that required for hydrated trical.cium. phosphate, and it- also contains 

C02. As no crystalline impurities greater '(;han 2 percent exist even 

after heating, carbonate-apatite must be the essential constituent 

of bone. The COs groups could substitute for F ions, although the 

carbonate-apatite structure is probably closer to that of mimetite 

than that of' f1uorapatite. The X-ray diffraction patterns o:f o, OJ!(, 

and COs apatites can be distinguished in mixtures. Cas(P0..,}2 was 

made by adding ll8.2BP04 solution s~owl.y to a solution containing excess of Ca(:N03 ) 2 , and hydroxylapatite was prepared by hydrolysis of 

this Cae(P04)2 with neutral ammonium citrate solution. F ·i·s present 

in excess in many phosphorites and euerystalline apatitej it may be 

present as submicroscopic fl.uori te, or perhaps replacing 0 in P04 
groups. Excess Ia is also believed to be structural. Chlorine is 

usually less than 0.03 perc.ent. In aging ot recent phosphorites 

( Curaf~ao, Cenozoic deposits ) both hydrated tricaleium phosphate and 

hydroxylapatite are changil:lg to t+uorapatite. In the fossilization. 

of bone, earbo11ate-apati te also changes to f'luora.pati te, whose 8110UD.t 

increases with the age of the bone. According to the rates. ot these 

changes, Pleistocene deposits should consist chiefly of fluorapatite. 

z. 8. A. 

1IJM 32 

Hendricks, s., Jefferson, M. E., Mosely, V. M., ~e crystal structure 

of' some natural and synthetic apatite-like substances: Zeitsehr. 

Kristallographie 81, pp. 352-369, 1932. 

Apatite, ehlorapati te, pyromorphite, mimeti te, and vanadini te 

all have atomic arrangements derivable from space group C6h 2 - C63 /M.• 

Pyr0110rphite, mimetite, and vana.dinite form an extensive though illcomplete solid solution series. Polysphaerite, kampylite, hedyphane, 

and endlichite are also members of this series. Chl.or- and fluorapatite f'ar:m a complete solid solution series, as do fl11or- and hydroxylapatite. The occurrence of many other minerals of similar composition 

suggests that F in fluorapatite can also be replaced by C03 , S04 , Si,204, 

0 1 Br, or I. 

Artificial preparations: 

Hydrated triealeium. phosphate was prepared by adding a solution 

of B&sP04 slowly to a solution with excess Ca(N03 ) 2 • The preeipi tate 

was washed with a sa.tur~ted solution of Cae(P04J2 until the filtrate 
was free of nitrates; the salt 1m.s then dried at 50°C o 

Rydroxyla:patite w.s :prepared by hydrolyzing Ca.s(P04)2 Yith 

neutral ammonium. ei trate. 

Oxyapati te was prepared by igniting hyd:roxylapati te or bone to 

.constant weight at 50°Co 

Chlorapatite vas prepared :f'rom Ca.Cl2 and a.nhyqxou.s Cas(P04J2 

fused together in platinum in stoichiometric propo~tions at llt-00°C. :l 

In nature -chlorine seldom replaces more than half the F in 

fluorap!lrti te, although chlora.pati te and fluorapatite form a "Complete 

solid solution.. The a/c ratio decreases with increasing Clo The 

reason for this lim.it.ed replaceJDent is that the ionic radius of' Cl 

is lo8l A, Yhereas that of F is lo36 A.o The authors suggest that 

this situation is analogous to that of' dolomite and calcite, and that 

the structure may even be similar, Yi th Cl and F. atoms in an ordered 

arrangement. Pyromorphite, mimetite, vanadinjte, and chlorape.tite 

have structures similar to Mehmel 1 s fluorapatite; fluorapa.ti te and 

hydroxylapatite bave llaray-8zabo's fluorapatite strueture. 

Z. So A. 

Kazakov,. A. V ., The fluorapatite system of equilibrium in the collditions 

of' formation of' sed.imen.tary rocks g .Aka.do Nauk. U .. R .s .S. ~ Geol. ser o 1 

vel. 144, noo 4o, pp. 1-21, 1950. 

Data on the goechemistry of fluorine are presented. The f"luorix.te• 

phosphorus ratio o:f the earth*s crust and of soils is near that of fluorapatite (percent F /percent P = 0 0 0893) ; it rises to 2 o 0 in fresh -waters,. 

8. 0 in oeeau waters, and. attains still higher values in drying relict 

basins.. The systellt CaO-P~-HF-1I~ l48.S studied princ1.pally by the 
40 

35 

30 

• ; 25 

I!: 

a. 

~ ::I 

cr 

= 20 

'5 

.., 

E 

u 

~ 15 

' ., 

0 

~ 

a-10 

2 

5 

5 10 15 

' 

0 

D 

pH: 6.4 

Caa(P0.)2·0.5 HtO pH=6.4 to 

7.0 

Ca10(P04)a(OH)t pHS. 7.0 

(). Gel 

20 

Mg Ca0/100 cm1 of liquid phase 

Isotherm at 25°C 

{Kazakov, 1937) 
8 

c 

0 

+= 7 :1 

0 

• 

.._ 

0 

:I: 6 

a. 

9 

c 0 . 

:;:8 

:1 

0 

• 

0 

:1::7 

a. 

hours 10 25 35 

Time in days 

10 25 

Time in days 

Change in pH with age of mixture 

(Numbers are experiment numbers) 

35 

21 

(KtJZflkov, /9$1) 
method of slow crystallization from solution. Reagents were mixed during 

30 to 50 hr at a rate of about 5 mg P205 per liter per hour, and the 

resulting phases left in contact for one to two monthso The reagents 

used were~ Ca(OH)2, HsP04, and NaF (sometimes HF) o All solid phases 

wer.e checked chemically and optically, and some solid phases were 

checked by X-ray and thermal analysis. The fields of stability of and 

transition points between solid phases are shown in the following table: 

Field of stability 

Solid phases Composition of the liquid phase at equilibrium 

-----· 

CaO (mg/l) P20s (mg/l) F (mg/l) pH 

CaHP04 • 2H20 4o 82 --- 6.5 

CasP20a·H20 12-4o 82-5 --- 6.5-7ol 

Cas(P04)sOH 6-1200 5-0.001 I --- 7ol 

Cas(P04)s(F,OH) 6-1200 5-0.001 0-9 7.1 

Ca5 (P04)sF 9-1210 5-0.001 1.5-17 7.1 

CaF2 9-1210 5-0.001 2.5-18 --- Ca(OH)2 1212 0 0 --- Ca.sP~a • H20 + 

Cas(P04)s(F,OH) 12 5 --- 7.1 

Ca5 (P04)sOH + 

Ca(OH)2 1210 0.005 0 --- cas (P04 )sF + 

CaF2 + Ca(OH)2 1200 OoOOl 2.5 --- CaF2 + Ca(OH)2 1213 0 2.G -3.0 --- i 

Ka 37 

Kazakov, A. V~, The system Ca0-P~ -H 0 in the field of low concentration 

(synthesis of tricalcium phosphate and hydroxylapatite): Sci. Inst. 

Fertilizers and~nsectofUngicides Trans. 139, pp. 3-73, Leningrad, 1937. 

Phosphoric acid in solution in sea water at depth is brought, under 

certain conditions, to a shallow zone where partial pressure of C02 

diminishes enough to allow precipitation o:f apatite. Work on precipi ta-
tion of hydroX7lapati te at the isotherm 25• gave the.· appended ·diagram. 

Crystallization was accomplished b;y mixing solutions ver;r slowly 1 

maintaining a constant composition, and mixing eonstantl;r (the l.ongest 

mixing took 17 days, at the rate of 2 mg P~5 per litre per hour) • 

~e entire experiment was conducted with l.iquid reagents--CaO in RsP041 

and Ca(OH)2 • The solutions took one to three months to come to 

equilibrium; pH of the solutions was checked periodicall.,-. Kazakov 

criticizes Bassett for his use of solid reagents, and for miXing the 

reagents too quickly. Solid phfl ses produced were: hydro:x:ylapati te, 

brushite, tricalcium phosphate [given as Cas(P04J2 ·0.5ll201.. See 

diagrams followiDg • 

The data were obtained by: X-ray of solid phases,; determination 

of pH of liquid,; chemical analysis of liquid and solid phases,; differential thermal analysis of solid phases; and optical examination of 

solid phases. 

nement, R., Basische Phosphate zweiwertigen Metalle. IV. StrontiumHydroxylapatite: Zeitschr. anorg.u.allg. Chemie 242, pp. 215-221, 

1939. 

Experiments were conducted in the hydrolysis of seeondary· Sr 

phosphate (SrBP04). 

Hydrolysis for two weeks in water had no effec~. 

'\ 

Hydrolysis in N/10 NaOJ:I at 4o°C. gave Sr h~oxylapatite; results . 

were checked by chemical and X-ray methods. 

Hydrolysis at 4o°C. in phosphate buffer soJ.utions of pH 6.8 and 
46 

8.3 had no effect on the strouttua salt. n.eaent compares this with. 

the similar behavior of the Ba phosphate and eon~rasts it with the 

hydrolysis of Ca and Pb phosphates to apatite. Hydrolysis in a phos- · 

phate buffer solution of pH ll.O at 4o°C. resuJ.ted in incomplete eonversion to Sr hydroxylapatite in four weeks. Sr hydroxylapatite was 

precipitated from a boiling solution of' lfaOH, la.sP04, and SrC12 • 

Chemical analysis of' the product gave the ratio Sr:P04 = 1:0.67. 

Ca, Pb, and Ba hydroxylapatites may also be precipitated ·in this 

way. Adsorption of excess P04 throws off the Sr:P04 'ratio.· Pure· 

Srs(P04)2 may be made by miXing stoichiometric proportions of Sr:e,PafJT 

and SrCO~s, and heating at 1000 °C. 

Pure 3Sr3 (P04 )2 ·Sr(OR)2 may be made from a stoichiometric mixture 

of Srs (P04) 2 and SrC03 , heated for seven hours in a current of steam 

at 1150°C. and cooled at 300°C. in a current of steam. 

The unit cell of Sr hydroxylapatite is compared with those of 

Ca, Pb, and :Ba hydroxylapati tes • 

. Ionic radius a e c:a 

Ca3.0 (P04Je ( OH)2 1.06 9.4<> 6.93 0.737 

SrJ.0 (P04)e(OH)2 1.27 9.74 7.20 0-739 

PbJ.0 (P04)e(OH)2 1.32 9.88 7-32 0.741 

BaJ.o(P04)e(OH)2 1.4:; 10.19 7.70 . o. 756 
\\ 

nement, R. 1 Versuehe uber Isomorphie in der Wagneritgruppe: llaturwi~s.., 

Berlin, Jahrg. 29, Heft 20, pp. 301-302, 1941. 

Synthesis by fusion of Ms4{Si,P,S) 20sF2 is impossible; but mixcrystals may be made by substituting Li or :Ia · for one Mg, S for one P; 

the powder diagrams still give a wa.gnerite pattern (rhombohedral (sic)). 

C&~.aOsC12 is 1110noclinic, and is not isomorphous with wag:neri te. It 

may be made by fusing CasP~a with CaC12 ; the arsenic analog may be 

sim1larly s,nthesized (Ca~saOaC1 ) and has essentially the same powder 

pattern. By heating Ca..,P~ Cl2 in steam at 900°C. for 4 hours, or with 

llaOJI in a closed tube at l00°C. for 10 days, hydroxylapatite was synthe-

·sized. !he author concludes that basic phospbat~s and arsenates tend 

to crystallize as apatites rather than as wagnerites. 

KD 41 

Klement, R., and Dihn, P., Isomorphe Apatitarten: Nat~)Jktr4n, 

Jabrg. 29, Heft 20, p. 301, 1941. 

Synthetic ellestadite Ca1 oSi3 Ss024F2 has a = 9.54, c = 6.99, 

c:a = 0. 732, d(calc) = 3.00, d(meas) = 3.06. Hydroxyl-ellestadite 

produced by treating ellestadite with steam at 1000°C. has similar 

lattice constants. Hydroxyl-ellestadi te cannot be made directly by 

fusion. On heating, hydroxyl-ellestadite l.oses water and lime and 

~eli. to a high-temperature sodium calcium phosphate structure. 

Fl.uorellestadi te retains its apatite stru.eture on heating. Synthetic 

expected to have a sJIB.l.ler structure than fiuorapati te, actually has 
a larger structure. 

a c c:a d{calc) d(meas) 

Baaea. (so .. )eFa 9.49 6.87 0.724 2.81 2.81 

Ca1o(P0-&)eF2 9.36 6.88 0.732 

nem.ent, R., and Dihn, P., Isomorphe Apatitarten: Zeitschr. Elektro• 

chemie 48, pp. 334-336, 1942. 

ne authors synthesized apatite-type minerals "WJ.tb. Si and S replacing P by fusing stoichiometric mixtures of the various materials. !he 

products were X-rayed and the lattice constants calculated. (See table 

l. ) The various fluorine compounds were converted to hydrox,.l OCJ~~>ounds 

by treatment with steam at 1100°C. Most of the cOJtpOunds tend to torm 

the hydroxyl compound with the water vapor in the reaction mixture. 

Ellestadi te must be treated with steam at 1100 oc. to form, the hydroxyl 

compound from the fiuorine compound. 

Table 1 

Lattice constants, apatite material 

a 

Ca1oP6 024F2 apatite 9-36 

Ca1.0SiP4S02,.F2 9.45 

Ca1.oSiP4S024(0H)2 9.44 

Ca1.oSisSsOa.,.J'a ellesta.d.1te 9.54 

Ca1.oSisSs02 4(0R)a 9.54 

hydroxyl-ellestadite 

9.52 

b 

6.88 

6.96 

6.96 

6.99 

6.99 

6.87 

6.90 

c:a 

0.732 

0.736 

0.737 

0.732 

0.732 

0.724 

0.725 

calc. meas. 

3.09 3.13 

3.o8 3.01 

3.00 3.06 

3.00 3.07 

2.81 2.81 

2.98 2.97 
The addition of Si and S to the lattice ~owers the aeltiJig point 

and the stability of the e~ound. . 

When Si and S are substituted tor P, . there must be other substitutions to balance the valences of the formulas; when l'a and S substitute for Ca. ari.d P, the lattice should shrink but there is a sall · 

increase in the a axis. 

Table 2 

Lattice constants, apatite ma:t~ria1, 

composition different from. ideal formula 

a b e:a eal.c. meas. 

Ca1.oPeOa~2 apatite 9.36 6.88 0.732 :;.19 :;.2 

Ca1.o.sSiPsOa..,F2 9-35 6.79 0.726 3-29 3.2 

Cae.sPsSOa4Fa 9.46 6.91 . o. 731 3-05 :;.oa 

Ca1.o.sSi2PsS024Fa 9.4o 6.81 0.724 :;.23 :;.20 

.. 

Cae.sSiPsS2Da4Fa 9.46 6.91 0.731 :;.o4 3.10 

:laaCasSiP4SOa4Fa 9-39 6.89 0.734 3.24 :;.10 

Minerals with a ·disordered apatite structure were synthesized by 

fusion of the appropriate components. X-ray examination of the products 

indicated that the material had lattice constants similar to those 

of apatite. (See table 2.) structures with 11 and with 9 m.etaJ. ions 

were synthesized. 

Phosphorus can be repl.aced in the apatite lattice partly or 

wholly by S and/or Si without changing the lattice type; however, 

the metal ion m.ust be balanced according to the charges. Therefore, 

the synthesis of a ITa-Ca-sulf'apatite is possible. The corresponding 
hydroxylapatites can be prepared with the exception of the abovementioned Ba-ca-sulfapatite. 

~e apatite lattice can also in certain circUJBStances show disorders, with excess or lack of metal ions. 

~. B. 

nement, R., B~ter 1 F., and K~hrer, K., Bildet sich Carbonata.:Patit in. 

W~serigen Systemen: Zeitsch:r. Elelttrochemie, Band 48, nr. 6, pp. 

334-336, ~942. 

The authors discuss the work of previous investigators and the 

role of the COs ion in the apatite structure. :latural. apatites .•Y 

contain up to l.O percent C02 , bones and teeth have less. ~e authors 

fee~ that C cannot substitute for Pas suggested by McConnell. because 

this substitution im;pl.ies a.n unknown coordination (4) for carbon. ~ . . . 

!be authors precipitated calcium phosphate in the presence of 

sodium bicarbonate and analyzed their results. From the lack of a 

stoichiometric ratio of CaCOs to P205 and the direct correspondence 

of the amount of C02 in the precipitate with the amount of lialiCOs 

added, they concl.ude that carbonate apatite does not form in this 

mnner. 

ney x-rayed the various precipitates and, by comparison of the 

reflection angl.es of various lines, concl.~ded that the apatite l.a.ttice 

had not been changed and therefore that no carbonate had been added 

to the lattice. ~bl.es of anal.yses and X-ray angles are given. 

~. B. 
51 \ 

~ . Korber, F., and ~omel~ H., UJa.tersuch\lJlgen ube,r l'allt•Phosphorsallre und 

Kalk-PhosphorsAure-Kieselsh.ure Verbindullgen: Zeitschr. Elektroeheaie 

38, 8a, pp. 578-582, 1932· 

The authors criticize the oxyapatite concept on the ground that 

onJ.y one F position would be occupied; they sugest that both F positions may be taken by 0, and the valence balanced by s\ibsti tution of 

rare earths for caJ.cium. Such a prod:aet maY be mde by :tu.sion and 

may give an apatite pattern with. intensities differing slightl.y from 

a normal apatite pattern. No other data on this synthesis are given. 

pattern; the prodnct of this is hydroxylapatite made by reaction with 

the humidity of the air. Hydroxylapatite was also made by mixing 

lf&.sP04 + Ca{B~) 2 with excess N140H. This hydroxylapatite contained 

adsorbed P04 which gave it a cao:P2 05 ratio smaller than the ratio 

characteristic of pure hydroxylapatite. The authors present the same 

obJections to the carbonate-apatite concept as to oxyapatite. 

Larson, H. W. E. , Prepa.ra.t1 on and properties of mono-, di-, and tricalcium phosphates: Ind. and Eng. Chemistry, Anal. Ed., 7, no. 6, 

pp. 4ol-4o6, 1935. 

Monoca1cium ;phosphate monoh;r¢r:ate (CalL& (PO..,) 2 • R.:aQ ) was prepared 

from a 5:1 = P.a()5 :Ca0 mixture (as Ca(OH) 2 and B3P04 solutions). The 

solutions were evaporated slowJ.y and t~ supernatant liquid decanted; 

the crystaJ.s were filtered, then washed with alcohol and ether.- The 

yield was 66 percent of the the.oreticaJ. yield. The Ca.O and P~s. content 

f 

\ 
52 

J 

ot the crystals was within 0.5 percent of that required by thEt formula. 

' 

The crystaJ.s were white, rhomboidal, and finely twinned; pet/ographic 

study showed that they were optically (-), 2V = 70 o, and bad· the following refractive indices by sodium light: nG = 1.5292, nM = 1.5176, nP = 

1.4392.: OpticaJ. and X-ray study showed that the crystals were triclinic. 

When the crystal.s were heated at loo•c. for a long time, they lost l mol 

H~; heating at 200-205 °C. for J.O weeks caused a loss of 2. 5 mols H~, 

which. the author accounts for by the following reaction: 

Other dissociations take place under varying temperature conditions. 

Solubility data for this salt in C02 -free and C02-saturated wate~ are 

given. 

DicaJ.cium phosphate tetra.hydrate (CaBP04 ·4H~) was prepared by 

recrystallizing conunercial dica.lcium phosphate. Analysis for CaO and 

P205 checked within 0.5 percent of the amount required by the formula. 

The crystals were pale-yellow rhomboidal plates, monoclinic_, optically 

(-), with refractive indices by sodium :Light nG = 1.5516, IL'M = 1.5457, 

nP = 1.5394. One mol H~ was lost at 108°C., one more at 150_0 , a.nd 

two more from 150° to 185°. Solubility data are given for this salt 

Tricalcium phosphate mono~ate (Ca-s(P0 ·R~) was prepared f'rom 

48 hours at 65-70°C.; pH was kept between 7 and, 8 by addiiion of ~ute 

:N}40H. The precipitate was filtered, washed f'ree of chlori~s with a 

small amount o:f water, air-dried, and ground. cao and P~5 were within 

0. 5 percent of the amount required by the :formuJ.a. The crystals were 

too small for petrographic study; X-ray diffraction patterns of the 
53 

freshl.y prepared salt and of' the salt heated at 950-970°C. showed 

tbat the lines of the heated salt. were closer together and more 

prominent than those of the freshly prepared sa.J.t; both patterns 

differed from those of oxy- and hydroxylapatite. ~e crystals lost 

very l.ittl.e water on heating between 65 and l00°C.; heating between 

950 ° and 970 °C. drov:e off one molecule of water. Solubility data 

tor this salt in C02 -free and C02 -saturated water are given. 

Lorah, J. R., Tarter, H. V., Wood, L., A basic phosJ)hate of calcium 

and strontium and the absorption of ealeium phosphate by triealeium 

phosphate: Am. Chem. Soc., Jour. 51, pP. 1097-11061 1929. 

Trical.cium. phosphate was prepared from C~(P0 •Ha<> by adding 

.carbonate-free ammonia until the solution was al.kaline; the precipitate 

'WS.S washed with water o 

Tricalcium phosphate prepared in this way contained small. amounts 

of'· a more basic phase. Tristrontium phosphate vas ·prepared in. the same 

way. Tribarium phosphate was prepared by dropping Ba.Cl2 into a so~ution 

of :laaBP04, and a.lkalizing with carbonate-free NaOH. 

Hydrol.ysis: the hydrolysis of Ca3 (P04 ) 2 in water or 0.5 or 0.05 

M lfaQH produced hydroxylapatite after several days of carbonate.:.:f'ree. · 

boiling with removal of supernatant liquid. A similar but slower reaction occurred with Sr3 (P04)a. 

Ba or C&Cl2 + Na2BP04 + H20 + IaOH produced apatite plus tribariua 

or tricaleium phosphate. 

Adsorption: Apatite prepared by hydrolysis of Cas(P04,)2 was placed 
in contact with Ca(OH)2 solution for 3 days to 6 aonths; it showed a 

normal adsorption curve, except that after 6 months it showed greater-thanusual adsorption. !he authors suggest that this may be due either to 

slow penetration of Ca(OR)2 into the interstices of colloidal apatite, 

or to solid solution {agreeing with Bassett, Cameron, and Bell). · 

Adsorption experiments with Cas {P04J 2 were limited to 16 hours, to 

. . 

prevent formation of apatite. The adsorption curve was normal and stronger than that of the more basic salt. The authors conclude that equilibrima between· the two "basic" phospba.tes is on the acid side of ·neutrality. 

~zi, Carlo, Apatiti sintetiche con cromo trivalente ed esavalente: 

Periodico Miner. anno 12, no. 3, pp. 343-378, 1941. 

I. History of the study of substitutions in the apatite group. Borgstrom 

(1931) found a complete series from. ehl.orapatite to 3Cae(P04)2•IaCl with 

2.91 percent Na~ (by synthesis from Ca.s(P04 ) 2 + Ca.Cl2 + BaCl). 

Larsen and Sbarmon (1931) found 4.:;4-7 .11 percent Na~ in lewistoni te, dehrni te, ( crandalli te?) • 

K substitution is possible onl.y in very s:maJ.l amounts. 

SUbstitution of rare earths ·1s possibJ.e, and occUrs in natural 

apatites up to 5 percent. 

MgO substitution is possible in limited quantities, probabJ.y 

around 2 percent. 

~ere may be complete substitution of SrO.; there is more SrO in 

pegmatitie than in ~matie apatites. 
SUbsti tut1on ·of BaO is possible; its 11m1ts a.re 'UJlkaown .• 

There is probably very limited solid solution of apatite and 

PJromorphi te. 

There is more JfnO in pegmati tie than in m.gmatie apatites. Its 

oxidation state in apatite is uncertain. 

Fe and Al may substitute in very small quanti ties. 

Cd, Be, Sl, are present in spectrographically perceptible .amounts 

in :natural apati tea. 

~e substitution of COs in apatites is -iJ'l-t. ~-

discussion. 

~ substitution of V and of As is possible, as is that of S · 

and Si. S03 may substitute in sma.ll quanti ties. 

In bri tholi te, Ce and Si substitute for Ca and P. M04 aud W04 

ma7 substitute in mimeti te, va.nadini te, and pyromorphite; their 

substitution in apatite ma:y therefore be possible. F and Cl can 

substitute freely for each other; traces of Br and I have also been 

f011D.d. 

OH is a well-established substitution; the possible substitution 

of 0 is under diseussion. 

The possibility of substituting CrcQs, CrO,s, or both, bas been 

described in natural apatites and demonstrated for synthetic mimetite, 

va.na.dini te, and p~omorphi te. 

II. Synthesis 

In the first four syntheses, simple chromo-chlorapatites crystallized at the top of' the mel.t as :Long :f'ra.gile neeclles, at the bottom as 
shorter prisms vi th bipyramids; maximum length of neeclles 'W&s 2 em. 

!rb.e crystals are green, the color intensifying to bJ.ue green w1 th 

increase in chromium; the deepest-colored crystals have a very slight 

biaxial character. Pleochroism of chromo.;,.chlorapati tes is E = clear 

yellow green, 0 = deep blue. The trivalent chromium ·in the apatites 

was formed by reduction of hexavalent chromium by HCl from the com.• 

bination of cac12 with absorbed water. It was not possible'· even in 

the presence of NH~0 , to form crystals free of cr+++. Procedure 

of crystallization in all cases was to fuse reagent~ for 6 hours at 

ll00°C.' cool slowly, and wash with water and. dilute acetic acid, 

in which excess of reagents dissolved. In an attempt to form crystals 

containing only cr+++ a mixture of 18 g CaCl2 , 8 g Ca.s(P04)2, and 1 g 

CrP04 was fused; this produced some colorless, transparent crystals 

with 0.06 percent cr+++, indices by red light nO = 1.670, nE = 1.669, 

by yellow light nO = 1.667, nE = 1.666, by green light no·= 1.65;, 

nE = 1.651; some very fine green crystals were also formed, due to 

partial oxidation of trivalent chromium. A complete anal.ysis of the 

crystals formed in experiment III led to the f'ormu.la 

Ca1o(P,cr+3,cr+6)e024Cl2. 

Unit-cell dimensions calculated from powder patterns of products of 

experiment IV are: c = 6. 73, a = 9. 56, e: a = 0. 704. Calculated from 

this cell and fram the molecular weight derived from the analysis of 

the product of experiment III is the specific gravity ;.22; the measured 

specific gravity is 3.21. 
57 

The soda-ehramo-ehlorapatites resembled the ·chra~a•ehlor-apatites 

except for being a little m.ore yellow green. Chemical &J2&1Jsis ot thell 

showed an excess of Ca over the theoretical formula. SUbstitution of Cr 

in apatites might be accounted for by: 3p+5 = 2Cr+6 + -cr+' J this is not 

borne out by the variable cr+3:er+6 ratios obtained. !he a\tthor su.ggests 

that, where cr+6:er+3 is greater than 2:11 some oJcyapatite to:t11S to 

compensate the excessive Charges. 
Experiment Reagents {grams) cr+3 cr+6 

number CaC12 Cas(P04)a CaCr04 NaaCr04 op "/J 

Chlorapatite --- --- --- --- --- --- I 27 12 1 --- 0.20 0.18 

II 27 12 :; --- 0.14 0.66 

III 27 10 5 --- 0.51 0.96 

IV 27 1 5 --- 0.14 2.92 

VIII 27 9 --- 3 0.54 2.20 

IX 27 6 --- 6 0.30 2.84 

Red light Yellow light 

nO nE nO nE 

1.670 --- 1.667 --- 1.672 1.670 1..668 1.666 

1.68:; 1.681 1.676 1.674 

1.688 1.686 1.682 1.68o 

--- --- 1.710 1.707 

--- --- --- --- --- --- --- --- - -~----

Green light 

nO nE 

1.653 --- 1..655 1.652 

1.665 1..66:; 

1.670 1.668 

--- --- --- ---

--- ---

Na light 

nO nE 

--- ---

--- --- --- --- --- --- --- --- 1.693 1.690 

1.701 1.698 

\J1 

en 
?9 

. . " " . . JIUJ.ler, Marcel, Die J'aJ.lung und die rontgenographische Untersuehung 

des Misebkristallsystems Ca1o(PO,.Je(OH)2 -- Pb1o(P04)e(Oll)2: Hel.v. 

ChirA. Acta, vol.. 30, fase. 7, pp. 2069-20&>, 1947. . . 

A. series of hydroX7l.apati tes ra.nging in composition ·froa l.OO percent 

Ca1o(P04)e(OH)2 to 100 percent Pb1o(P04)e(OH)a was synthesized by precipitation followed by hydrol.ysis according to the method described 

below. 

Ca or Pb nitrates (or a. mixture of the two), KH2 PO..,, and 0.1 

normal. BaOH( C02-f'ree) were dropped together from 3 burettes in stoichiometric proportions, and reacted in this way: 

where Me is a divalent metal and X is a. monovalent anion. 

100 em? of KHaP04 solution were dropped into one liter of boiling 

water containing 10 em? of' bromo-·creso1 purple ( 0 .1'-') • This excess of 

phosphate was added first so that Pb (OR) 2 wou1d not precipitate. Then 

0. 5 cm3 of ca or Pb solutions (or mixture) and more KH2 P04 were added, 

and the solution neutralized vlth NaOH to red violet (pH about 6.5). 

After stirring for one minute, the solution w.s again neutral.ized. 

'.rhis process was repeated until the desired amounts o:f Me* and P04 

ions were in solution. !rhe volume of the soluti.on \vas kept at one 

liter by addition of distilled water. Precipitates were filtered out, 

hydrolyzed f'or 15 hours in one liter of boiling water, filtered out, 

and dried at llO °C. C02 - free water- was used throughout. 

The products of these syntheses were analyzed for Ca, Pb, and P04. 

X-ray diffraction patterns show a progressive change in spacings from 
6o 

100 percent Ca to 100 percent Pb, proving that actual mix-crystals 

were formed. Crystal size vas improved by heating the products at 

6oo oc. for 4 hours, and cooling quickly. Spacings of crystallographic 

planes were calculated for the pure end members, and tor Ca5 Pbs(P04)e(OH)a, 

as well as the following lattice dimensions. 

lim. )...2/ Q2 a c 

6.-..71'90° 

CaJ..0 (P04)e(OH)a 2.68o 9.4o 6.92 

CasPbs(P04)e(OH)a 2.650 9.62 7.08 

PbJ.o{PO~tJe(OH)a 2.-425 9.89 7.28 

In general, the lines on the X-ray diffraction patterns broaden 

as the reflection angle increases. In the series f'rom Pb5Ca.s{P04)e(OH)a 

to PbJ.o(P04)a(OH)a1 the splitting of the K'a doublet can be seen with 

difficulty, but from Ca7Pbs(P04 )6 (0H) 2 to Ca10(P04)e(OH)a it disappears 

completely. In the last instance, the broadening of lines with 

increasing reflection angles is so great that only lines with reflection angles of 25°-,, 0 can be measured, whereas in the series 

CasPbs(P04)e(OH)2 to Pb1o(P04)e(OH) 2 , the lines with reflection angles 

greater than 41 o can be measured precisely. 'fbis broadening may be 

caused by the variation in lattice constants owing to inhomogeneity 

in the chemical composition of these apatites. It is possible that 

homogeneous single layers of different composition may precipitate one 

above the other, or that a single mix-crystal may have some such in-

. hoaogenei ty as a zonal structure. As this broadening of the lines is 

apparent to the same extent in the pure end-members as it is in the 

intermediate members of this series, the broadening may be explained_ 
~ 5,S 0 

~ _5.0 

o-

.a~ c: \0 4.5 

at 

E .5! 4.0 

:I -

c: :S 3.5 

Phase I 

-1.0 -o.5 0 0.5 1.0 2.0 

Uranium in solution at equilibrium 

(log if/ml) 

1.5 

1.0 

-0.5 

3.0 

c 

0 

+= 

::::s 

. 0 ,_ 

c:E 

-~ 0.. 

Fig. I. The adsorption of uranium on bone ash 

(Neumon1 Neumon, _Moin ond MulfYOil, 1949, p. .. 
61 

by variation of lattice eons~ts owing to defective structure in 

microcrystals, and especially by the very small size of the individual 

crystallites. The d spacings of the· same lines decrease w1 th increasing 

Pb. 

:leuman, W. F., Beuman, M. w., Main, E. R., and Mulrl'fm, B. J., !rhe 

deposition of uranium. in bone. IV. Adsorpt.ion studies in vitro: 

Jour. Biol. Chemistry 179, pp. 325~334, 1949. 

The first three papers of this series are concerned with in vivo 

studies of uranium metabolism. in rats. 

Adsorption studies described in this paper were carried out on 

bone ash, prepared from the shafts of long bones (of' rabbits) boiled 

in a three percent solution of KOH in ethylene glycol., and on fresh 

bone, ground and dried to constant weight. Particle size had no 

perceptible effect on the adsorptive capacity of fresh bone or bone 

ash. The fl.uid medium was 0.025 M lfa.liCOs; ita pH_ remained between 

7.2 and 7. 3 throughout the experiments • The sol.utions were prepared 

by dil.uting aliquots of a saturated stock solution of U containing 

equimolar amounts of U02 (CHsC00)2 and sodium acetate with a concentrated 

solution of NaHCOs. The final solutions were equilibrated at atmospherie pressure with a mixture of 5 percent C02 , 95 percent Oa; one 

ml of solution was added to 2 mg of bone ash, reequilibrated with 

the COa-02 mixture, and sh&ken for 48 hours to equilibrium. ~e sol.-

utions were then analyzed for u, Ca1 and P. The initial U concentration vas varied from 5 to 1500 ·7 per mJ.. See f'igure l. 
62 

Eighty to 4oo 1 per ml of uranyl acetate were added to uraniumfree solutions saturated with bone ash. Precipitation was erratic; 

the solutions were therefore salted out with BaCl. The precipitates 

thus obtained had a molecular ratio of U:P = 1:1. Assuming 3 mol.ecules 

of water per mol.ecule of u, their composition corresponded to a mixture of lia(U02) (P04), Ca(U02)2(P04)2, Mg(U02)2(P04)2 in the molecular 

ratio 23:2.7:1. 

Synthetic bone ash sol.utions were prepared using 61/ml each of 

CaCl2 and NaHP04 in 0.025 M liaHCOs. 8o to 4oo7U/ml. were added to this 

solution. The solutions were equil.ibrated as before with the C02-02 

mixture, centrifuged after standing, a.nd the supernatant liquid analyzed. 

U remained sol.uble up to 8o 1/ml., but exchanged for Ca; from 8o to 

about 450 1/ml, uranyl phosphate precipitated on bone. Above 450 11 

both the U and P present in sol.ution show an apparent i~crease, probably 

due to the formation of colloidal uranyl phosphates. 

All the processes described above are shown to be reversible. It 

is shown that fresh bone has less adsorptive capacity than bone ash. 

Below 8o 1/ml., U remains solubl.e under the conditions described 

above; however, the U content of bone increases. As the amount of U 

fixed by bone depends on the relative amounts of the phases present, 

a surface-limited reaction is suggested. Particle size does not affect 

the adsorptive capacity of bone, because the surface of bone ash is not 

a fUnction of particle size. A plot of U initially in solution against 

U finally present in bone ash suggests a dissociation reaction. The 

uranyl group, therefore, probably replaces Ca, and is bound by phosphate, 

the only group present on the surface in large enough concentration. 
6; 

lleuuan, W. F., Beuman, J(. W., Main, E. B., and llul.ryan, B. J., !he 

deposition ot urauium in bone. V. Ion exchange studies: Jour. 

Biol. Chemistq 179, pp. 335-34<>, 1949. 

~e bone used in these experiments consisted of': bone ash, boiled 

in alkaline glycol; tresh bone dried and gro\Uld; and glycol ash heated 

in a muffle :furna.~e at 4oo°C. for 6 hours and at 700°C. for 6 hours. 

Solutions ·were prepared as described in the preceding article. Bxchange capacity of' bone relative to Ca and P was studied by means of' 

p32 and ca45. Bone ash prepared by boiling in al.ka.line glycol showed 

a greater exchange and adsorption capacity than fresh bone, but glycol 

ash heated in a muffle fUrnace had practically no exchange or adsorption capacity. Saturating glycol-ashed bone with U reduced its capacity 

to exchange ca and P; the adsorption of 1 mol of' U reduced exchangeable 

Ca and P each.by 2 mols. 

About twice as much Ca as P is exchangeable, indicating a surface 

concentration of Ca in bone. Bon-phosphate anions must therefore be 

associated with surface Ca. (Heating bone ash at a high temperature 

may convert it to a different structure, and thus inhibit or prevent 

adsorption by exchange of Ca.. EBJ) 

Neuman, W. F., Neuman, M. W., Main, E. R., and Mulryan, B. J., The 

deposition of uranium in bone. VI. Ion eompeti tion studies: 

Jour. Biol. Chemistry l.-79, pp. 341-348, 1949. 

Bone ash prepared by heating in a.lkal.ine glycol at 200 °C. was 

used f'or these experiments. Using 87 7U /mJ. and increasing concentra.-

tions of NaHCOs, the capaei ty of' bone ash to adsorb U fell off with 
increasing pH. Using 45 7 U/ml and an 0.025 M solution ot l'aHCOs, 

concentrations of' cac12 or lla.HP04 were varied. Excess Ce. reduced 

the concentration of' P in solution and the adsorption ot U. The -

concentrations of ca and P in solution showed an inverse relationship. At pll 8, addition of U to the system increased the Ca. in 

solution but did not decrease P; therefore at pH 7.3 the effect of' 

varying Ca:P ratios on U adsorption are due to variations in the 

Ca. ion. Variations in the P ion may be due to the limited solubility 

of some compound of Ca. and P. There is a linear relationship between 

Ca. and U present in solution at equilibrium, and an inverse relationship between · Ca in solution and U in bone; these facts show that there 

is direct competition between Ca and U for the surface phosphate groups 

of bone. 

A discussion of' uranium metabolism follows. 

Uranium might be fixed in the skeleton in three different 

ways: by binding with protein carboxyl groups, with carbonate 

groups, or with phosphate groups. There are too few protein carbo~l groups in bone to account for its adsorptive capacity reJ.ative 

to U; these groups are not present in bone ash, which shows a higher 

adsorptive capacity than fresh bone; protein-bound U is highly 

dissociated. There are likewise too few carbonate groups in bone; 

the complexes U02-0-CO-R are too highly dissociated; although the 

groups U02(C03 )i and U02 (C03 )J form in solutions with excess carbonate or bicarbonate, they are too large for the apatite lattice. 

There is a good correlation between exchangeable phosphate groups 
and their affinity ~or V. Uranyl pyrophosphate is onl7 sl.ightl.y 

dissociated. As one Jiol. V inactivates two phosphate groups, it 

is possibl.e that U combines with two adjaeent POi groups to ~ora 

a structure similar to uranyl. pyrophosphate. The merfpntm eapaeity 

of uranilDD. adsorption by bone is equivalent to 14() percent of the 

surface ·P04 groups. There is direet competition. of Ca and U tor 

these posi tiona. At high lfalliCOs concentrations, both the bicarbonate and P04 groups eompete for U. At a high pH, OH and P04 groups 

compete for u. 

!he author plotted a curve of conductivity against composition 

in ·the system lfsP0 --ca.(OH) --C0 ~-H~. He obtained the curve by 

measuring the conductivity at equiJ.ibrium at 15° of' a. series of mixtures of cac<>s in an 0. 5 li solution of EsP04, bubbl.ing C02 ,through 

the sol.u.tion lllltil. equilibrium. was reached. The curve had a single 

break at the mixture 0.587 PaOs, 0.464 CaO, 'Where the sol.id phase 

had the contposition caBP0 ·2H~. In more basic mixtures, CaCOs also 

precipitated out. In the absence of C02 , mixtures of 0. 5 If 1JsP04 

with 0. 5 li Ca.( OH) 2 in various proportions showed a break in the curve 

at the composition caBP04 •2Ha(), a.t the composition Pa05 /CaO = 0.30-0.28 

(for the l.iquid phase) • The precipitate at this ~econd break. was 

colloidal, and the result is therefore uncertain. i'he author suggests 

that the rise of conductivity at the basic end may imply that either a 

more basic phase than Cas(Po4 ) 2 has f'orated, or that excess cao has been 

absorbed by Cas (P04) 2. 
66 

Pieruecini, R. , SUJ.la possibill ta di ·iD.trodurre all.uminio, ferro 1 pi011.bo 

o molibdeno nel. reticolo delle apati ti: Soc. toscana sci. nat. Atti 

54, pp. 256-67,1947. 

The author discusses the various substitutions reported to take 

place 1n apatites and apatite-like minerals. The possibility of intraducing Al, Fe, Pb, and Mo into the apatite lattice was investigated; 

these elements were expected to substitute only ill small quantities. 

The minerals were synthesized in all cases·by fusion of salts at 

high temperatures and checked by measuring the ref'racti ve indices of 

the resulting material. In all cases smaJ.l crystals were formed. 

Aluminian apatite was synthesized with 1.88 percent Al.~sf!/ its 

composition was checked by chemical a.na.J..ysis: CaO = 53.70 percent, 

Al.~s = 1.88, P~5 = 39. 73, Cl = 5. 76, H20 = 0.33, total = 101.4o, 

less (0 for CJ.2 = 1.30) = 100.10. nONa = 1.6681, ~a = 1.6643, 

nOpJ8 -nEma = 0.0038. Maximum amount of Al~3 is probably 2 percent. 

Iron-bearing apatite was synthesized in a closed metal tube.gj · 

!he product obtained was never homogeneous; some of the crystals were 

clear; some were violet colored. With slow cooling liBgnetite -was formed. 

The uncolored crystals had nOJ'a = l.. 6720, 1 .. 6745; uniformly colored 

areas of violet crystals gave nOma = 1.6745, 1.6736, 1.6738, nExa = 

1.67ll, 1.6704, 1..6705. rea<>s deter..nined by visual spectrograph was 

'!/ By fusing a mixture of aluminum phosphate, calcium phosphate, 

and calcium chl.oride at 1100° for one hour and cooling slowly. 

gj By fu.s ing ID.i.x'i;ures of iron phosphate, calcium phosphate, and 

calcium chloride for 45 minutes to 6 hours and cool.ing slowl.y. 
0.03 - Oo05 percent; v:f.olet crystals contained about 2 percent Fe~s· 

As Ca substitutes for Pb in some ~rals, a mixture of Pb phosphate, 

Ca phosphate, and ca chloride was fused at ll00°C ·f'or one hour and 

treated to remove other products. Elongate crystals gave nO = 1.6693. 

Other mixtures containing lead were fuSed and indices measured. Elongate 

crystals contained 0.07 percent PbO .. 

An attempt was made to SJ'D,thesize Mo apatite. Calcium molybdate 

:~.::_ii';·-!';. 

was one of' the fusion products; some apatite with OoOl percen~b~ 

determined spectrographically, and nO == 1.6646, DE = 1.6615, was obtained by fusing calcium phosphate, calcium chloride, and calcium 

molybdate. 

To B.o 

R 41 - Rivi~re, Andre, Recherches e~rimentales sur la s~dimentation pbosphat6e 

en milieu marin: Acad. sci. Paris Comptes rendus, vol ... 212, pp. 1038-

1041, 1941. 

(RH4)3 P04 liberated from decayed organic matter can coprecipitate 

with carbonates as calcium diphosphate and ammonium magnesium phosphates; 

this can happen only in concentrated solutions and vi th a pH of' about 6. 

The first precipitate is rich in ammonium magnesium phosphate. In the 

presence of' Ca.COs this salt produces phospho-carbonates in equilibrium 

with mono- and di-phosphates in solution, the relative amounts depending 

on the pH. Precipitation is almost complete at pH 8(normal a.J.kalinity 

of' sea water). The solubility of' Ca.s{P04 ) 2 is also linked to the pHo 

This salt dissolves mostly as dicalcium phosphate. 
68 

The following experiments were performed at atmospheric pressure 

and room temperature. 

l) Seawater was shaken for severu hours with excess dicalcium 

phosphate, then filtered; the pH fell from 7. 7 to 7.4, the P20s in 

solution increased sharply. The dical.c ium phosphate substitutes for 

the bicarbonates normally present in seawater, whereas the C02 thus 

liberated lovers the pE. lio d.! calcium phosphate can precipi ta.te in 

sea-wa.ter unless more than 1000 times the normal concentration is present. 

2} The preceding experiment was carried out with C02 bubbling 

through the solution; the amount of phosphate in solution increased 

as the pH fell to 5.8. 

3) Some of the solution from experiment 2 was filtered and freed 

of C02 by bubbling C02 -free air through it; there was an abundant 

precipitate of calcium and magnesium diphosphate plus a small amount 

of carbonate (probably as a·phosphoca~bonate). The filtrate bad a 

pH of 7 .2. In such an environment, a rise of pH would cause precipitation of diphosphates, which would then convert to tricalcium phosphate by diagenesis. 

4) Anothe;r part of the solution from experiment 2 was filtered 

and left in contact with excess CaCOs in a c.losed system. The pli 

rose to 6.2 without a;ny perceptible change in the amount of P20s in 

solution. C02 was then eliminated as in experiment 3. After fil tra.-

tion, the solution had a pH of 7.32, and the phosphate in solution 

had diminished. The phosphate probably precipi ta.ted on the excess 

Ca.COs a.s "triealcium. phosphoca.rbonate ( dahlli te) " • Thus, phosphatic 

solutions can phosphatize CaCOs if the pH rises because of algal 
activity or simple ag~tation,." ,~s rep.laoement can ~e place with 

mnch less phosphate in so~ution than can simple precipitatibD. 

Variations of pressure seem to have little influence on the 

reactions described above; variations in temperature affect the solubility of C02 and thus affect these reactions. 

Sanfourche, · A. , Recherches sur 1 'acid.e phosphorique et lea phosphates. 

I. La formation des phosphates al.eaJ.ino-terreux basique a: Soc. 

ehim. France Bull. 53, pp. 951-963, 19.33· 

Experiments were made vi th 0 .lli 1JsP04 , plus basic solutions of 

Ba, Sr, and Ca. 

In the case of Ca, the author used a saturated solution at 20 •c. 

(0.44 lf) -- crystallization 'WB.S much slower than nth the Ba or Sr 

salt. ~e author postulates a series of' more and more basic phosphates, 

tending towards .C8.4P,209 (purely chemical study of precipitates-EBJ). 

SH 33 

Sanfourche, A., and Henry, J., Recherches sur 1 'aeide phosphorique et 

les phosphates. v. Lea reactions d'hydrolyse des phosphates dicalcique et tricalcique: Soc. ehim. France Bull. 53, pp. 1210-1217, 

1933. 

!he hydrolysis of' brushite is questionable, because, according to 

these authors, it must be seeded with Cae(P04 ) 2 • Once started, it 

proceeds until Cas(P04 ) 2 is present as a solid phase, and hydrolysis 

of this last ensues. For large quantities of_brushite relative to 

wter, equilibrium. is rapicUy attained. The discontinuity in the temperature curve at 75 °C. means that the solid phase inverts here to 
/ . 

I' 

. ·-~-.:. ; _:;: 

\ 

\ 

1 . 

monetite. Cae(Po )~!vas p~d :trOll ca(liOs)a atld :r&aBP04 with -excess. I( 

I 

ot am.onia. During t-.shiDg to reBWve maorda, hydrolysi-s 'Mgan, giYirJ.S- , ~ 

'i 

a JllOre basic produc~. According to these authors, the :normal pro4uets 

ot this hydrolysis ke apatite and brushite. -

SSI: 32 . . ~ . ' .-. 

Sehl.eed.e, A., Schmidt, _ W. , and Kindt, B. , Sur _lCEmn1mis iter Cal.Ciuaiphosphate 

und Ape.tite: Zeitschr. Elektroehemi-e, Band 38, Br. Sa, 1932. 

Ex.Periments : 

J.) Brushite, hydrolyzed in warm water for 500 h.ours 1 _ gave a 

hydroxylapatite pattern. 

I 

2) Commercial. triphosphate (sic) gave a ~oJcy"lapatite patterD 

and, in one case, brushite lines, before hydrol.ysis; after a,drolysis 

it gave a hydroxyla.pati te pattern only. 

3) ~etracalcium phosphate made by f'u.sing a mixture of c011111le%-eial 

triphosphate and cao gave a pattern close to but not exactly like apatite. 

On heating, this gave apatite and cao lines; on hydrolysis, it gave a 

s:i,mpJ.e apatite pattern. 

4) SUicocalcium;phospbate was made by fusing collllaC!rcia.l triphosphate, CaO, and quartz. When this vas hydrolyzed in cold water 1 the pa.t-:-

tern changed only slightly. These authors bel.ieve tltat no real vicalcium phosphate exists. They synthesized hydroxylapa.ti te from 30 g 

phosphate ( tricalcium ? EBJ) and 500 cc KOH ( •. 5 B) boiled for 67 hours 

in 12 days in C02 atmosphere; the product was decanted to- neutrality 

Vi th water, washed with ether and aJ..cohoJ., dried in air; it save an 

apatite pattern. This prodnct vas then drie_d at 1050 °C. for ana.J.ysis; 
/ 

"/ 

i~s CaO:Pa()s ratio vas too low and 'WB.ter too high for apatite; when 

heated to fusion, -the CaO:Pa()s ratio approaehecl tbat of--apatite, _but 

wa"ter was lost gradually. At ab011t 9()0°C. the amount of water aacl the 

C&O:Pa()5 ratio corresponded to those ot hy"droxyl.apatite rather than to 

those ot the oxyapatite which has been supposed by previous authors to 

-

exist at this temperature. !rhese authors do not bel.ieve in -the existence 

of carbonate- or su.lf'ate-apati tes, and are doubt:ruJ. about cbl.orapatites. 

At temperatures above 1500 °C., hy"droxylapati te dissociates to a mixture 

ot trieaJ.eium and tetracal.cium. phosphate. 

~omel., . Gerhard, Untersuchtmgen uber " die Bil.dung eines halogenfreien 

Apatits aus basischen C&J.cium;phosphaten: Zeitschr. physikal. 

Chemie, Band 158, Abt. A, pp. 422-432, 1932. 

(}xJrapatite is not likely to exist, because it is at the eutectic 

C&O·P~ and 4cao·P~ , and beeause of the substitution of 1 oxygen 

for 2 F. :levertheless, an apatite does exist in the system. Ce.O-P~5 

below 14oo°C. When 4caO·P~5 was heated und.er a. p:aessure of 0.3 - 0.5 

lBB1 Hg, no apatite fol"'..ed; however, when this same compound was heated 

in air, hydroxylapatite formed. When it was heated in dry air or 

oxygen, no apatite formed. X-ray diffraction patterns suggest that 

lt.cao • P~5 JDa.y have a deformed apatite structure. 
J, 72 

z 16 - Zabonmi, .J'erru.cio, Qaelques o'bsenations sur la com;positiqn clea apatites: 

A:ca.4: sci. Pari9_ -Comptes ~-~ndus lp2ji,c~P· 919-921, 1916. 

Pasion o~ Cas(PO .. )a and CaCla proclu.ced. .a chl.c.?rapatite witla Yflr7 

weak bire&iDgellce. haiDg cas(PO.,)a with excess •ac1 p.ve CrJBtala 

with a birefringence of 0.0050-o.()()58, averasiDS 0.0()531 &Dal7&1s o~ 

which gave the formula 4.34 Cas(P0.)2 ·C&Cl2 (but these erJStal.& bad 

1.56 percent Ba, 4.85 percent Cl) • The author lists other apatite 

a.Da.l.yses leading to the formula mCas(P04)2·Ca[O,(OH)a, Fa,Cla,COs] 

where • is greater tban 3; but all these anal)'Ses show an excess of 

cao .. 

z 23 - Zambonini, Ferrucio, Uber die Mischkristalle, velche die Yerbind.ungen 

des Caleiums, Strontiums, Bariwns, und Bleis mit jenen der seltenen 

Erden· bi1den: Zeitschr. Krista.llographie Band 58, pp. 226-2921 1923. 

!he author discusses histories of syntheses of various compounds, 

and substitutions of Ca, Sr, Ba, Pb, for some of the "rare ea.rths"(sic). 

Synthesis was attempted from. the following mixtures llith the results 

noted: 

Ca(NOs)2 and Y(BQs)3 - mix with difficulty 

Sr (BOs) 2 and Y(B03 )s - with dif:fieul. ty 

PbS04 and ~i2"(S0 3 - unsuccessful 

Ce2(M004)3 and PbMo04 - successful 

Ce2(Mo04)3 and CaMoO• - successful 

Ce2{Mo04)s and SrXo04 - successful 
. l 

. J ., 

} 

lltla(Jio04 )s and~ - nceesstul 

Pra(llo04)s and ~. • neeessf\11 

l 

1 

"Dil(•oO• )s and PJ/jo()" - auc:eesstu:L .; 

La2(•oO.,)s and ~· - aueeessfUl 

Iaa(llo04)s and G~., - necessful. 

laa (MoO,. )s and S,:..iioO,. - neeess:tu.l 

l.aa(JloO•)s and BaMoo., - Slleeesstul. 

Ya(llo04)s and PbMo04 - auecess:ru.J.. 

Ya(R004)s and CaM004 - auee~ssful 

Y2(Rb04)s and c&Ko04 and Ce2(Ko04)s - sueeesstul 

Cea(V0.,)8 and PbWO., - successful 

Ce2(wo.,)3 and eawo4 - successfUl 

CeP04 and Pbs (P04) 2 - successful 

Pure Pbs(P04,) 2 was opt. (-), had no ano-.lies; (lolo)a(Olio) had 

an average value of 6o 01'; it was uniaxial and melted at lOl,•c. 

The max1MWI mixture contained 3-5 percent CeP04 by weipt: at 

5 percent CeP04 , a eutectic occurred at looB•c. 

Mix-erystaJ.s vith 2 percent CePO., reeellbled t~e pure Pbs(I'O.)a 

crystals, but had a slightly lower nE, and higher birefringence; 

dispersion -was aaOiial.ous in yellow and green. 

Indices of refractiOD: 

Mix-crystals vi th 

2 percent cero. 

nO 

1.9549-1.9994 

1.9587-1-9999 

nE DO-d 

1.9232-1.9618 0.0317.0.0376 

1.9227-1.96o0 o.o360-o.o399 
74 

Cerium-bearing apat~~e 

1.37 g Cas(PO.,Ja and 3 s C&Cla were fued at 1150•c. 1 washed with 

water after slow C:ooling; the crystals were 1.5 X o.; mm in size,. 

colorless to greenish, opt. (-); they had a birefringence of o.ooo8 

(Ia) and sp. gr. =~ ;.14. 4 g Cas(P04J 2 and 9 s C&Cla were heated 6 

hours at ll00°C.; the crystals were 2.5 X 1.0 mm in size, colorless 

or sky blue; a:c was 1:0. 7038; the birefringence •s o.ooo9-o.ooo6; 

crystals were zoned parallel and perpendicular to c; nO was 1.6642-

1.6747. 

2 g Cas(PO.,J2 and excess BaCl were heated 5 hours at 900•c.; the 

birefringence vas 0.0053 and analysis led to the formula 4.}4 CB.s(PO.,)a• 

CaCla; the author suggests solid solution with Ca.s(P0.)2 • 

A mixture of Cas(P04)a, CeP04, and li&Cl vas heated for 5 hours 

but the pro<iuct shoved only traces of Ce; however 1 mixtures •de 

with excess C&C12 instead of BaCl were successful. 

1.37 g Cas(P04)a and 0.08 g CePO" and·; g CaCla were heated to 

ll50°C. 1 cooled sl.owly, and •shed with Ha(). This produced a mixture 

of chlorapatite with minor amounts ot chlorspodiosite and monazite. 

The ehlorapati te was uniaxia1 (-) 1 birefringence = 0. 00051 sp. gr. = 

3.165, 'W&tercl.ear, homogeneous, and contained 1 percent CePO..,. JUxing 5.48 g Cas(P0.) 2 , 0.8 g CeP04 and 12 g C&Cl2 and heating to 1200•c. 

gave a col.orless chlorapatite with a birefringence of 0.001 containing 

1.6 percent CePO~. 

A mixture of 1.37 g Ce.s(PO-t)~t, 0.49 1 CeP04, and 3 1 Ca.Cla heated 

to l4oo °C. produced a mixt'tl.re of violet needles and short crystals; 
75 

the birefringence was 0 .001, and nOxa = 1.6672. !he cey-stala richeat 

in CePO• had a sp. Sr• of 3.166--all the above products had, 1a ad.tition, 

crJ'Btalline CePO•. A Jlixture ot } g Cas (PO• )2 aa4 2 1 Cel'O• ud 6 1 

C&Cla heated for 6 hours at 11oo•c. produced s.all colorless apatite 

crJ&tals, birefriqence = o.oolt., ~.=1.6703, sp. gr. = 3.3-3.18, ud 

containiDg 8 percent cePO •• 

A mixture of 2 g CePO• and :3 g C&s (PO•) 2 and 6 g C&Cla heatecl at 

11oo•c. for 24 hours produced colorless apatite crystals with DO • 

1.666-1.673, nl = 1.665-1.672, and 13 percent cePO.,. Apatite• containiq 8 percent and 13 percent CeP04 turn yellow on heating. 

"Diclpi'WI"-'t!earing chlorap&tite and chlorspocliosite 

1.}7 g Cas(PO.)a, 0.1 g "Di "PO"' and 3 g C&Cla heated to 118o•c. 

produced a Dlixture ot eblorapati te and ehlorspodiosi te. !he apatite 

was transparent, colorless, sp. gr. = 3.135-3.170, contained 3 percent 

"Di "P04 , and had the same optics as the pure synthetic ch.lorapatite. 

1.37 g Cas(PO.,)a, 0.2 g "Di "P04 and 12 g Caela heated to 1ooo•c • 

. produced pale-violet crystals of ehlorspodi~site. 

3 g C&a(P0,.)2 , 2 g "Di"PO.,, and 6 g CaC12 heated 6 hours at :uoo•c. 

save "Di"PO•, a little chlorapatite, end ehlorspodiosite wi~~ 9 percent 

"Di "PO•· 

Yttrium-beariDg ehlorapati te 

3 g C&e (PO .. Ja, 0. 7 g lPO.ft, and 6 g CaCla heated for l.5 hours at 

ll00°C. after ••hiDs with water produced ehlorapatites with nO = 1.669 

(therefore yttriua-bearing), and yellowish crystals (not innstipted) 

with 6.3 percent '!PO•. 
Theoretical discussion 

When absolute differences in molecular voluae are considered, 

most of these isom.orphotls substitutions are- not permissible, but 

when the difference in molecular volume is taken relative to the 

smallest molecular volume in question, this relative difference 

does not exceed that in certain natural series. This difference 

can further be reduced by considering the compound of -smallest 

molecular volume as a double or triple salt--e.g. CaCla--(LiCl)a; 

(SnS)3 --Sb;zSs. 

!he change in interfacial angles is not a straigbtline tunetion 

of percent substitution. 
77 

AUTHOR INDEX 

Page 

Arnold, P. W" . . . . . 19a 

Bassett, HG 20 

Belopol'skii, Ao P., Taperova, A. A., Serebrennikova, M. T. 

and Shul'gina, M. N. • . . . • . . • . • • . 25 

Brasseur, Henri Ao L., and Dallemagne, Marcel J. t 20 

Bredig, M. A., Franck, H. H., and Fuldner, H" (+932} 22, (1933} 24 

Carobbi, G. 

Chaudron, Go , and Wallaeys; R. • • 

Clarens, J. , and Brune ton, M. 

Clark, N. A. 

Clarke, Frank Wigglesworth . 

I 

( 1925) 25' ('1950) 26 

(i949) 28, (1950) 30 

28 

• • :e • • 28 

0 • 0 :· • 

Dallemagne, M. J. , Brasseur, H o , and Melon, J" • :· 

19 

31 .. 

Eis·enberger, Sidney; Lehrman, Alexander; and Turner, W. D. 38 

Eitel, Wilhelm . " • 

Elmore, Kelly L., and Farr, Thad D 0 

Fouretier, Georges • 

Greenwald, Isidor 

, 

Hebert, Claude • . 

j. • • 

33 

37 

39 

39 

4o 

Hendricks, S. B., Hill, W. L., Jacob, K. Do, and Jefferson, M. E. 42 

Hendricks, S., Jefferson, M. E., and Mosely, V. M • ., • 

Kazakov, A. V .• 0 

Klement, R. 

Klement, Ro, and Dihn, P. . . . 

(~937) 45, (1950) 44 

. (1939) 45a, (1941) 47 

(!1941) 47, (1942) 48 
78 

Klement, R., Huter, F., and Kehrer, K. 

Korber, F., and Tromel, H. 

Larson, H. W. E. 

Lorah, J. R., Tarter, H. V., and Wood, L. 

Minguzzi, Carlo o • 

MUller, Marcel -r • • • 0 • 

Neuman, W. F., Neuman, M. W 0 , Main, E. R., and 

Page 

50 

51 

51 

53 

54 

59 

Mulryan, B. J. . . . . . (IV) 61, (V) 63, (VI) 63 

Pallu, R .• 

Pieruccini, R. 

Rivi~re, Andr~ 

Sanfourche, A. 

Sanfourche, A. , and Henry, J. 0 • • • • • o 

Schleede, A., SchmidtJ W., and Kindt, H. • o 

Tramel, Gerhard . . 

Zambonini, Ferrucio . . 

• • • • • 0 0 .• 

• • • 0 0 • • 

70 

71 

(1916), (1923) 72 

10121