Gold in Minerals and the 

Composition of Native Gold 

Gold in Minerals and the 

Composition of Native Gold 

By Robert S. Jones and Michael Fleischer 

GEOLOGICAL SURVEY CIRCULAR 612 

Washington 1969 
United States Department of the Interior 

WAl.TfR J. HICKEL, Secretary 

Geological Survey 

William T. Pecora, Director 

Free on application to the U.S. Geological Survey, Washington, D.C. 20242 
CONTENTS 

Page 

Abstract -----------------------------------------------~----------------- 1 

Introduction -------------------------------------------------------------- 1 

General geochenrlcal considerations ----------------------------------------- 1 

Gold in minerals ------------------------------------------------------ _ 2 

Composition and the fineness of gold ---------------------------- ___ 13 

References cited --------·------- _____________________ ______________ ____ _ 15 

TABLES 

'fABLE 1. Major gold-bearing minerals ----------------------------------- __ 

2. Analyses of precious metals in minerals made before 1955 _______ _ . _ 

3. Analyses of gold in minerals made since 1954 ---------------------

Page 

2 

3 

10 

4. Variation in fineness of gold with depth, Lily mine, Transvaal, South 

Jlfrica -------------------------------------------------------- 14 

5. Fineness of mill bullion prior to 1882 at the Homestake nrlne, South 

Dakota -------------------------------------------------------- 15 

Ill 

GOLD IN MINERALS AND THE COMPOSITION OF NATIVE GOLD 

By ROBERT S. JONES and MICHAEL FLEISCHER 

ABSTRACT 

Gold occurs in nature mainly as the metal and as 

various alloys. It forms complete series of solid solutions with silver, copper, nickel, palladium, and 

platinum. In association with the platinum metals, gold 

occurs as free gold as well as in solid solution. 

The native elements contain the most gold, followed 

by the sulfide minerals. Several gold tellurides are 

known, but no gold selenides have been reported, and 

only one sulfide, the telluride-sulfide mineral nagyagite, 

ii:; known. 

The nonmetallic minerals carry the least gold, and 

the light-colored minerals generally contain less gold 

than the dark minerals. 

Some conclusions in the literature are conflicting in 

regard to the relation of fineness of native gold to its 

position laterally and vertically within a lode, the 

nature of the country rocks, and the location and size 

of nuggets in a streambed, as well as to the variation 

of fineness within an individual nugget. 

INTRODUCTION 

This report on the occurrence of gold in 

minerals and on the fineness of native gold 

was prepared as background material for the 

Heavy Metals program of the U.S. Geological 

Survey, an intensified program of research 

on new sources of heavy metals, including 

gold. 

GENERAL GEOCHEMICAL CONSIDERATIONS 

Gold belongs to group Ib of the periodi.c 

table, as do silver and copper. Its atomic number is 79, and atomic weight is 197.0; it consists of a single isotope. Its metallic radius 

is 1.44A., univalent ionic radius 1.37A., and 

trivalent ionic radius 0.85A. 

Gold is strongly siderophilic and somewhat 

chalcophilic; that is, it tends to be co,ncentrated in the metallic phase of meteorites, with 

1 

much lower concentrations in the sulfiie phase, 

and occurs in much lesser amount~ in the 

silicate phase. Gold occurs in natur~ mainly 

as the metal and as various alloys, especially 

with silver, and as intermetallic co:'llpounds. 

Laboratory studies show that gold can form 

complete series of solid solutions with silver, 

copper, nickel, platinum, and palla:dium. Gold 

is commonly present in association with platinum metals; most microscopic stuc"ies have 

shown that free gold is present in platinum, 

but a recent electron-probe analysis of ferroplatinum shows uniform distributioi' of gold 

( Ottemann and Augustithis, 1967). This distribution indicates that gold and platinum aTe 

present in solid solution. 

Several gold tellurides are known (table 1), 

but no gold selenides have been repC'...-ted, and 

the only minera~ in which gold is certainly 

combined with sulfur is the telluride-sulfide, 

nagyagite. Gold commonly occurs in sulfide 

minerals, but largely, if not entirely, as the 

free metal; it is uncertain whether any gold 

occurs in these minerals in true isomorphous 

substitution. 

It is even less likely that gold is present 

in ionic substitution in silicate miner·als. Mantei and Brownlow (1967) state, "Tl'e concentration of gold in the various minerals is probably due to an inclusion or entrappinr-- phenomena rather than to ionic substitutior. Because 

of its oxidation potenti.al, it would 1~<~ difficult 

for gold to become oxidized and thus be able 

to take part tn ionic substitution. Krauskopf 

(1951) states that simple ionic goli can not 

exist in geological environments, alth('mgh complex ions containing gold may form. Ringwood 

(1955) points out that Au+, because of its 
large electronegativity, would form a very 

weak covalent bond, and one which would prefer not to form. Thus the gold of a crystallizing 

magma tends to concentrate in the residual 

fluids. The factors which would control the 

amount of gold entrapped in a given mineral 

would be the concentration of gold in the 

magma at the time of crystallization and the 

type of crystal structure formed by the mineral." 

Helgeson and Garrels (1968), on the basis 

of thermodynamic calculations, think that all 

but marginal or low-grade hydrothermal native 

gold deposits form above 175°C and, at elevated temperatures, most hydrothermal solutions are probably distinctly acid. They believe 

that gold is present primarily in the form 

of aurous chloride complexes in contrast to 

the low-temperature considerations of Krauskopf (1951) and Cloke and Kelly (1964) who 

suggest that the aqueous species AuC17 is 

the principal form of dissolved gold in hydrothermal solutions. 

Goni, Guiiiemin, and Sarcia (1967) have 

investigated the stability of colloidal suspensions of gold and the formation of nuggets. 

Stable colloidal suspensions of ionic and even 

metaiiic gold can form which can be flocculated to form nuggets. Textures common in 

gold deposits can be reproduced in gold films 

formed by the diffusion of gold solutions 

through silica gel. 

Gold occurs in notable amounts in hydrothermal veins and in placer deposits, and to 

a much lesser extent in pegmatites and contact metamorphic deposits. Commo.n minerals 

_associated with gold in veins are quartz and 

pyrite. Some other common minerals associated with gold (Lincoln, 1911; Schwartz, 1944) 

are pyrrhotite, arsenopyrite, chalcopyrite, sphalerite, galena, molybdenite, tellurides, selenides, 

magnetite, scheelite, feldspar, sericite, biotite, 

chlorite, amphiboles, garnet, tourmaline, carbonates, and fluorite. 

GOLD IN MINERALS 

Minerals that have been reported to contain 

major amounts of gold are listed on table 

1. Many analyses have been made for some 

of the precious metals in minerals that contain little gold;: those made before 1955 are 

listed in table 2 and those made since 1954 

are in table 3. The more recent analyses have 

2 

been made by more sensitive methods, mostly 

by neutron activation, than the older ones, 

and values as low as 0.0003 ppi1. (part per 

million) are reported. However, comparatively 

few neutron activation analyses . of rock-forming minerals have been reportei in recent 

years. The older analyses tend to be significantly higher than more recent analyses of the 

same minerals. The highest gold values listed 

in tables 2 and 3 are reported for the native 

elements; next highest are for the sulfide minerals. 

Gold 

TABLE 1.-Major gold-bearing minerals 

Varieties: 

Au. Cubic, sp gr 19.3 (pure Au), 

decreasing with ircreasing content of Ag. Form!;; a complete 

series of solid solutions with silver 

(see electrum and silver, below); 

commonly contains 10-15 percent 

Ag. Also reported in percent: Cu 

(ma..."X: 20.4), Fe (ma.x 0.1), rarely 

Bi (max 2.9), Sn (max 0.3), Ph 

(ma..."X: 0.2), Zn (max 0.8), AI (max 

0.10), Mn (max 0.002). See section "Composition and Fineness 

of Gold." 

Electrum, (Au,Ag), argentian geld with >20 

percent Ag. 

Porpezite, (Au,Pd), palladian go1d with 5-10 

percent Pd. 

Rhsxlite, (Au,Rh), rhodian gold(?) with 34-43 

percent Rh. 

Auricupride (cuproauride) has generally been 

considered to be a solid solution of gold in 

copper, near AuCua in. composWon. Ramdohr 

(1967) states, however, that study of "red 

gold" from Laksia, Cyprus, has shown the 

presence of three· distinct phases Au-Cu solid 

solutions, the compound AuCua with a 

characteristic violet color, and the compound 

Au Cu. 

Aurosmirid, aurosmiridium ( =aurian osmiridium) Au 19.3 percent. ProbabJy a mixture 

containing gold. 

(Palache and others, 1944, p. 111). 

Silver (Ag,Au). Aurian silver, with 0-50 

percent Au. 

Kiistelite=aurian silver. 

Gold-amalgam A112Hga(?) 

Au 34.2-41.6 percent. 

Maldonite Au2Bi. Cubic. 

Au 64.5-65.1 percert; Bi 34.9-

35.5 percent. 

Aurostibite AuS~. Cubic, pyrite tYf<:'\. 

Au 43.5-50.9 percent. 

Krennerite AuTe2. Orthorhombic. 

Au 30.7-43.9 percent. 

M iillerine = Krennerite 

Speculite = Krennerite (?) 
TABLE l._JMajor gold-bearing minerals-Continued 

Calaverite AuTe2. Monoclinic. 

Au 39.2-42.8 percent. 

Coolgardite =a mixture of calaverite, coloradoite, 

and sylvanite. 

Sylvanite (Au,Ag) Te2, with Au :Ag usually 

nearly 1:1, that is, AgAuTe4. 

Monoclinic. 

Au 24.25-29.9 percent. 

Goldschmidtite= Sylvanite. 

Kostovite CuAuTe4 

Au 25.2 percent (Terziev, 1966). 

Petzite AgaAuT~ 

Au 19.0-25.2' percent. 

Antamokite=a mixture of petzite and altaite. 

TABLE 1.-M ajor gold--bearing m.inerals-Concluded 

Hessite Ag2Te. Monoclinic, pseudocubic. 

Reported to contain as much as 

4.7 percent Au. 

Montbrayite Au2Tea. Triclinic. 

Au 38.6-44.3 percent. 

Nagyagite PbsAu(Te,Sb)4Ss-s( ?) • 

Monoclinic ( ?) . 

Au 7.4-10.2 percent. 

Silberphyllinglanz = N agyagite. 

Blatterine = N agyagite. 

Aurobismuthinite (Bi, Au,Ag) sSs ( ?) 

Au 12.3 percent; Ag 2.3 percent. 

Probably a mixture (Palache and 

others, 1944 p. 278). 

TABLE 2.-Analyses of precious metals in minerals made before 1955 

[Minerals containing higher amounts of gold are listed in table l. N. D., not determined] 

Mineral and locality 

Arsenic, As 

Germany, Andreasberg, Harz ___ _ 

Copper, Cu 

Gold 

(ppm) 

150 

Norway, Kviteseid --------------- 200 

Iridosmine, ( Os,Ir) 

Australia, New South Wales _____ 800 

U.S.S.R., Urals ----------------- >1,000 

Iron, (Fe,Ni) 

Greenland, Ovifak, Disko _______ _ 

United States: 

Cal).yon Diablo, Ariz _________ _ 

Holbrook, Ariz ----------------

Mexico 

1-5 

5 

10 

Coahuila ------------~--------- 1-5 

Chile, Corrizatillo --------------- 5-10 

Germany, Biihl, near Kassel _____ _ 

Czechoslovakia, Knyahinya ______ _ 

Portugal, Sao Juliao de Moreira __ 

Platinum, Pt 

.5 

10 

10 

Brazil -------------------------- > 1,000 

U.S.S.R., Urals ------------------ 500 

Platiniridium, (Ir,Pt) 

Brazil --------------------------

Schreibersite, (Fe,Ni) aP 

Portugal, Sao J uliao de Moreira __ 

200 

1 

Silver 

(ppm) 

Elements 

>1,000 

>1,000 

600 

5-10 

5 

1 

5 

5-10 

5-10 

1 

5 

>1,000 

200 

10 

Platinum 

(ppm) 

20 

>1,000 

>1,000 

5 

10-100 

10-100 

.3 

10-100 

10 

.2 

10-100 

10-100 

>1,000 

>1,000 

>1,000 

1.2 

Sulfides, arsenides, selenides, and tellurides 

Domeykite, CuaAs 

Mexico, Paracatas 

Argentite, AgsS 

Germany, Freiberg 

25 

200 

>1,000 5 

>1,000 4 

3 

Remarks Reference 

One sample __ Noddack and 

No·ldack (1931). 

Two samples _ 

Eight samples 

Do. 

Do. 

Do. 

In basalt ____ Goldschmidt and 

In meteorite _ _____ do ____ _ 

_____ do -----

In meteorite _ 

In basalt ___ _ 

In meteorite _ _ ____ do ____ _ 

One sample __ 

Eleven samples. 

Pe...,ers (1932). 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Noddack and 

Ncddack (1931). 

Do. 

One sample __ Do. 

In meteorite. Gold ""<'hmidt and 

Two samples. Peters (1932). 

One sample __ 

Two samples _ 

Noddack and 

Noddack (1931). 

Do. 
TABLE 2.-Analyses of precious metals in minerals made "efore 1955-ContinU6d 

Mineral and locality 

Gold 

(ppm) 

Silver 

(ppm) 

Platinum 

(ppm) Remarks 

Sulfides, arsenides, selenides, and telluride.-Gontinued 

Berzelianite, C111Se 

Sweden, Skrikerum 

Chalcocite, CusS 

United States, Butte, Mont -------

Bornite, CusFeS, 

Germany, Mansfeld --------------

Galena, PbS 

South Africa --------------------

Clausthalite, PbSe 

Germany, Tilkerode, Harz _______ _ 

Altaite, PbTe 

U.S.S.R., Altai ------------------

Alabandite, MnS 

Roumania, Nagyag, Siebenbiirgen __ 

Sphalerite, (Zn,Fe) S 

Germany: Silesia _______________________ _ 

Biihl, near Kassel -------------

Chalcopyrite, CuFeSs 

Germany: 

Clausthal ---------------------

Breitenbrunn, near Zwickau ____ _ 

South Africa: 

Transvaal, Rustenburg district __ 

Stannite, CusFeSnS, 

England, Cornwall 

Do -------------------------

Czechoslovakia, Zinnwald ________ _ 

Pyrrhotite, Fe1-xS 

Norway, Fl1ysa 

Germany, Biihl, near Kassel _____ _ 

South Africa, Transvaal ----------

100 

12 

8 

30 

250 

400 

2 

3 

.5 

20. 

.2 

<.5 

2 

6 

.2 

2 

.6 

1-10 

>1,000 

500 

>1,000 

>1,000 

>1,000 

>1,000 

30 

150 

5 

800 

100-

1,000 

100 

100 

100-

1,000 

100 

6 

4 

10 

.1 

.2 

.8 

40 

10 

.02 

0 

.1 

<.5 

.1 

.6 

8 

10-100 

One sample __ 

Six samples _ 

Four samples_ 

Five samples _ 

One sample __ 

~---- do -----

_ ____ do _____ 

Three samples 

In basalt ____ 

Fifteen sampies. 

-------------

·-------------

-------------

-------------

-------------

In basalt ___ _ 

From Merensky Horizon 

on Schildpadnest, 

Rustenburg 

district. 

Content of 

other elements: Cu, 

Co about 0.1 

percent; 

Pa, 10-100 

ppm; Ru, 

Rh, Ir, 0.1-

1 ppm; Os, 

a trace. 

lkoference 

Noddack and 

Nod<lack (1931). 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Goldscl~midt and 

Peters (1932). 

Noddack and 

Nodc1ack (1931). 

Goldscl ""llidt and 

Pete1·s (1932). 

Schneic!=!rhohn and 

Mori~z (1931). 

Noddack and 

Noddack (1931). 

Goldsd·midt and 

Peter~ (1932). 

Do. 

Noddac~ and 

Nodd .. ~k (t '"131). 

Goldschmidt and 

Pete1'" (1932). 

Schnei(i"erhohn 

(192S). 
TABLE 2.-Analyses of precious metals in minerals made before 1955-Continued 

Mineral and locality 

Gold 

(ppm) 

Silver 

(ppm) 

Platinum 

(ppm) Remarks Reference 

Sulfides, arsenides, selenides, and tellurides--Continued 

Troilite, FeS 

United States, Canyon Diablo, Ariz_ 

Mexico: 

Coahuila ----------------------

Ixtlahuaca ---------------------

Chile, Corrizatillo _______________ _ 

Esthonia, Tennasilm 

Niccolite, NiAs 

Germany: 

Eisel ben _____________________ _ 

Klettenberg, Sauerland ________ _ 

Austria, Schladming, Styria ____ _ 

Pentlandite, (Ni,Fe,Co) eSs 

Norway, Espedalen _____________ _ 

Germany, St. Blasien, Schwarzwald_ 

South Africa, Rustenburg district, 

Transvaal ---------------------

Siegenite, (Co,Ni)sS4 

Germany, Miisen near Siegen ___ _ 

Pyrite, FeS2 

Norway: 

Setesdalen 

Sulitjelma --------------------- Italy: 

Calceranica ------------------- Libiola, Genova Province ______ _ 

Boccheggiano, Grosseto _______ _ Chuch e Servetie _____________ _ 

Pestarena ---------------------

Lavanchetto -------------------

Alfenza -----------------------

South Africa: 

Rustenburg district, Transvaal __ _ 

Witwatersrand 

Sperrylite, PtAss 

Canada, Vermillion mine, Ontario __ 

0.5 

1-5 

.2 

.5 

0 

1 

10 

• 5 

6 

.5 

1.0 

1 

.4 

.4 

1.1 

.33 

.12 

.95 

200 

20 

6.5 

5-10 

3 

40 

10 0.5 

5 1-10 

15 6 

10 .2 

5 .3 

1()..-100 

10 .2 

100 

140 2 

10-100 .2 

5-10 

>1,000 .5 

10 

70 . 3 

10-50 

300 >1,000 

5 

In meteorite -

_____ do _____ 

_____ do _____ 

_____ do _____ 

_____ do _____ 

-------------

-------------

-------------

Two samples -

-------------

-------------

-------------

Fifteen sampies. 

-------------

-------------

Two samples _ 

-------------

------------- ----------------

---------------- Crystalline 

aggregate 

contained 

12 ppm Au 

and a crystal contained 0.93 

ppm Au. 

Two sampies. 

Nickeliferous_ 

Three samples 

Goldsclmidt and 

Peter~ (1932). 

Do. 

Noddack and 

Nodcack (1931). 

Goldscl midt and 

Peters (1932). 

Noddar.k and 

Nodc"ack (1931). 

Goldschmidt and 

Pete~s (1932). 

Do. 

Do . 

Noddack and 

Nodrlack (1931). 

Goldschmidt and 

Pete~s (1932). 

Schnei/lerhohn and 

Morftz (1931). 

Goldsc"midt and 

Peters (1932). 

Nodda~k and 

Noddack (1931). 

Do . 

Mingur.zi (1947). 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Schne~<ierhohn and 

Mo1.;tz (1931). 

Hegenann and 

Leybold (1954). 

One sample __ N oddack and 

N~dack (1931). 
TABLE 2.-Analyses of precious metals in minerals made before 1955-Continued 

Mineral and locality 

Gold 

(ppm) 

Silver 

(ppm) 

Platinum 

(ppm) Remarks 

Sulfides, arsenides, selenides, and tellurides--Continued 

Cobaltite, CoAsS 

Canada, Cobalt, Ontario _________ _ 

Norway, Skutterud --------------

Sweden, Tunaberg ---------------

Germany: 

Dreikonigsstollen Buchholz, Saxony 

Gliicksbrunn, Altenstein, 

Sachsen-~eine ---------------

Gersdorffite, NiAsS 

Germany: 

~lisen, near Siegen ------------

Friedensgrube, Lichtenberg, 

Oberfranken ----------------- Lobenstein, Vogtland, Thiiringen_ 

Michaelis Fundgrube, Triebel, 

near Zwickau ---------------

Ullmannite, NiSbS 

Germany: 

Miisen, near Siegen ------------

Salchendorf, near Siegen ______ _ 

Landeskrone, Willnsdorf, near 

Siegen ---------------------- Saffiorite, CoAs2 

Germany: 

Schneeberg, Saxony ------------

Dachsberg, near Riechelsdorf 

Rammelsbergite, NiAs2 

Germany, Gessellschafter Zug, 

Schneeberg, Saxony _________ _ 

Marcasite, FeS2 

Germany, Westphalia ____________ _ 

Arsenopyrite, FeAsS 

Norway, Skutterud --------------

Germany, Ehrenfriedersdorf, 

Saxony -----------------------

Molybdenite, ~oS2 

United States, Climax, Colo _____ _ 

Australia, Kingsgate, Glenn Innes, 

New South Wales -------------- Czechoslovakia, Zinnwald ________ _ 

Germany: 

Sadisdorf near Schmiedeberg, 

Saxony --------------------- Altenberg, Saxony ____________ _ 

Norway: 

Telemarken -------------------- Sorumsassen near Drammen ___ _ Rade, 0stfold _________________ _ 

Undalen ______________________ _ 

6 

10 

.6 

• 6 

• 8 

3 

10-100 

10-100 

5 

10-100 

20 

10 

.6 

.8 

6 

.3 

4 

8 

.6 

.06 

1-10 

.1 

5 

.2 

.6 

.6 

• 05 

.06 

6 0.1 -------------

200 2 One sample --

1 -------------

10 .5 -------------

10 .1 -------------

5 • 1 -------------

10-100 .1 -------------

10-100 .1 ------------- 1 -------------

10-100 .1 -------------

20 • 5 ------------- 100- ------------- 1,000 

10-100 .2 -------------

10-100 ------------- .5 • 1 -------------

6 -------------

100 .1 One sample __ 

90 • 4 Four samples_ 

10 -------------

100 .05 -------------

100 • 02 ------------- .2 • 05 -------------

10-100 1 ------------- 2 .2 -------------

4 .04 Three samples 

10-100 .05 ------------- 10 ------------- >100 With chalcopyrite. 

6 

Reference 

Gold:-1~hmidt and 

Pe+ers (1932). 

Nodcack and 

Ncddack (1931). 

Gold:~ehmidt and 

Pe~ers (1932). 

Do . 

Do • 

Do • 

Do. 

Do. 

Do. 

Do. 

Do . 

Do. 

Do • 

Do. 

Do . 

Do. 

Nodd~~k and 

Nocdack (1931). 

Do . 

Golds<'!hmidt and 

Peters (1932) 0 

Do. 

Do . 

Do . 

Do. 

Do . 

Do. 

Do. 

Do . 

Do. 
TABLE 2.-Analyses of precious metals in minerals made before 1955-Continued 

Mineral and locality 

Gold 

(ppm) 

Silver 

(ppm) 

Platinum 

(ppm) Remarks 

Sulfides, arsenides, selenid£s, and tellurides-Continued 

Skutterudite, CoAss 

Germany: 

Niederrasmstadt near Darmstadt_ 

Riechelsdorf, Hessen _________ _ 

Bieber, Hessen _______________ _ 

Frauenbreitunger, Saxony- ]deiningen __________________ _ 

Schneeberg, Saxony ___________ _ 

Hasserode, Harz ______________ _ 

Austria, Schladming, Styria ______ _ 

Tetrahedrite, CuuSb4S1s 

England, Cornwall ______________ _ 

Austria, Tyrol __________________ _ 

Germanite, Cua(Ge,Fe)S4 

South-West Africa, Tsumeb -----~­

Enargite, CuaAsS4 

United States, Butte, Mont _____ _ 

Argyrodite, AgsGeSs 

Bolivia --------------------------

Halite, N aCl 

England, Cheshire ______________ _ 

Germany, Stassfurt _____________ _ 

Sylvite, KCl 

Germany, Mecklenburg __________ _ 

Carnallite, KMgdla: 6H20 

Germany, Bernburg _____________ _ 

Pyrolusite, Mn02 

Czechoslovakia, Platten, Bohemia __ 

Cassiterite, SnOs 

Bolivia, Potosi -------------------

Indonesia, Bangka Island ______ _ 

Germany, Breitenbrunn near Zwickau, Saxony ______________ _ 

Czechoslovakia, Schonfeld near 

Schlaggenwald -----------------

South-West Africa: 

Sandamab ---------------------

Nubeb ------------------------

0.3 1,000 

2.7 10 

.1 1-5 

.8 10-100 

.5 100-

1,000 

5 10 

.8-.5 5 

Sulfosalts 

8 >1,000 

60 >1,000 

40 800 

1& >1,000 

90 >1,000 

Halides 

0.103 N.D. 

. 132 N.D. 

. 003 N.D • 

. 012 N.D. 

Simple oxides 

0.2 4 

.5 10-100 

.5 10 

.5 10 

.5 5 

.5 10 

.5 1 

7 

2 

.2 

.2 

.8 

0 

N.D. 

N.D. 

N.D. 

N.D . 

10 

. 2 

• 2 

Two samples _ 

Seven samples 

One sample __ 

_____ do ____ _ 

_____ do ____ _ 

Two samples_ 

One sample __ 

_____ do -----

----- do -----

Four samples_ 

·-------------

-------------

Three samples 

-------------

-------------

------------

Ref~renee 

Goldschmidt and 

Peter"' (1932). 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Noddack and 

Noddack (1931). 

Do. 

Do. 

Do. 

Do. 

Liversiige (1897). 

Do . 

Friedri ~k ( 1906) . 

Do. 

Noddack and 

Nodc.11ek (1931). 

Goldscl midt and 

Pete:--s (1932). 

Do. 

Do. 

Do. 

Do . 

Do . 
TABLE 2.-A"'Z.alyses of precious metals in minerals made before 1955-Contm:ued 

Mineral and locality 

Gold 

(ppm) 

Silver 

(ppm) 

Platinum 

(ppm) 

Oxide!f eontainintr uranium, thorium, or zirconium 

Uraninite, UOs 

Norway, Brevik ------------------

Czechoslovakia, Jaehymov --------

Thorianite, ThOs 

Ceylon --------------------------

Psilomelane, (Ba,HsO )sMnsOto 

Germany, Harz ------------------

Chromite, (Mg,Fe)sCrO, 

United States: 

Mineral Hills, Pa --------------

Lancaster County, Texas, Pa __ _ 

Norway, Feragen, Bebiet ----------

Hausmannite, MnaO, 

Sweden, Li.ngban ----------------

Columbite, (Fe,Mn) (Nb,Ta)sOe 

Norway, Arendal ----------------

Plagioclase, (Na,Ca) (Al,Si)2Sb0s 

South Africa, Rustenburg district, 

TransvaaJ --------------------- Pyroxenes: 

Bronzite, (Mg,Fe)SiOs 

South Africa, Rustenburg district, 

Transvaal --------------------- Diallage, Ca(Mg,Fe)SisOe 

South Africa, Rustenburg district, 

Transvaal --------------------- Olivine, (Mg,Fe)sSiO, 

South Africa, Rustenburg district, 

Transvaal --------------------- Gadolinite, Y sFeBe.SisOe 

Norway, Iveland -----------------

Arandisite, (tin silicate?) 

South-West Africa, Arandis _____ _ 

Hellandite, silicate of Ca and Y 

Norway, Kragero ----------------

0.1 2 

.03 5 

.05 2 

Oxides C4ntainintr OB 

0.2 

.2 

.2 

.1 

50 

Multiple oxides 

1 

1 

1 

10 

0.2 

• 1 

2 

1 

Multiple oxides eontainintr Nb, Ta, and Ti 

0.05 2 8 

Silieates 

<0.5 <0.5 

1-5 

.5 1-5 

.5 1.0 

.2 4 2 

.5 5 .2 

.1 .1 

8 

Remarks Reference 

One sample __ N odd ""ek and 

No·Jdack (1981). 

Two samples _ Do.. 

One sample -- Do • 

Two samples _ Noddack and 

Noddack (1981). 

Golds~hmidt and 

Pet1rs (1982). 

Do. 

Do. 

Two samples _ Noddr~k and 

Noc..fack (1981). 

Twenty-three 

samples. 

One sample --

Nodd~ek and 

Nod~ack (1981). 

Schnei~erhohn and 

Mor'tz (1981). 

Do. 

Do. 

Do. 

Nodda~k and 

Noddack (19:ll) 

Goldsc:'tmi<~t a'ld 

Peters (1932). 

Noddaek and 

Noddack (1981). 
TABLE 2.-Analyses of precious metals in minerals made before 1955-Continued 

Mineral and locality 

Gold Silver Platinum (ppm) (ppm) (ppm) Remarks R(>ference 

Phosphates 

Triplite, (Mn,Fe)J(PO.)F 

South-West Africa, Sandamab ___ _ 0.5 5 0.2 ·------------- Goldschmidt and 

Perers (1932). 

Nitrates 

Soda Niter, NaNOa 

Chile --------------------------- 0.110 N.D. N.D. One sample -- Liversidge (1897). 

Sulfates 

Anhydrite, caso. 

Germany, Pllimnitz -------------- 0.007 

Gypsum, CaSO. ·2Hs0 

United States: 

Salina, N.Y ------------------- .083 

Grand Rapids, Mich ------------ .083 

Kainite, KMg(SO.)Cl·SHsO 

Germany, PIOmnitz --------------- • 003 

Both Anoshin and Potap'yev (1966) and 

Shcherbakov and Perezhogin (1964) show that 

the gold in the quartz exceeds that in the 

feldspars by a factor of 2. 7. Shcherbakov and 

Perezhogin noted from the analyses of monomineralic fractions of igneous rocks that the 

average gold content decreases from magnetite 

and ferromagnesian silicates to feldspars. They 

reported (table 3) the gold content of the 

major rock-forming minerals as follows: 

quartz, 11 ppb (parts per billion); feldspa~r, 

4 ppb; biotite, 4 ppb; muscovite, 3.8 ppb; 

amphibole, 5.9 ppb; pyroxene, 16 ppb; olivine, 

14 ppb; and magnetite, 48 ppb. 

Mantei and Brownlow (1967) have made 

many neutron activation analyses of minerals 

from the Marysville quartz diorite stock (table 

3). The diorite has an appreciably higher gold 

content than the average diorite, and most 

of its component minerals have unusually high 

gold contents. The reported gold contents increase from quartz and feldspar ( 65 ppb) 

to biotite (76 ppb) and reach a maximum 

in hornblende (100 ppb). The gold content 

of magnetite was found to be only 37 ppb, 

in contrast to the findings of Shcherbakov 

and Perezhogin ( 1964) who report more gold 

N.D. N.D. One sample-- Fried~ick 1906). 

N.D. N.D. Silurian. One Linco1n (1911). 

sample. 

N.D. N.D. Mississippian. Do. 

One sample. 

N.D. N.D • One sample __ Fried"ick (1906). 

9 

in magnetite than in the silicat~ minerals. 

Mantei and Brownlow accounted fc¥ the lower 

gold content of magnetite, comparee- with other 

minerals they analyzed, by pointing out that 

the structure of magnetite is relatively closed 

compared to the structures of biotite and hornblende and that "magnetite may bave formed 

before the silicates, at a time wh~n the concentration of gold in the magma was fairly 

low." 

Badalov (1965) examined tl'~ average 

amounts of gold, silver, selenium, and tellurium 

in the disseminated copper-molybdonum deposits of the Almalyk district in t\e U.S.S.R. 

The sequence of the formation of the predominate minem:ls in the ores was from earliest to llatest: magnetite, molybdenite, pyrite, 

chalcopyrite, sphalerite, and galena. Pyrite is 

by far the most abundant mineral and carries 

3 ppm gold. Chalcopyrite is the :o;econd most 

abundant mineral and was the chief "coneentrator" of gold; it contains 22 rpm. Native 

gold is common, and gold tellurid ~s are rare. 

N oddack and N oddack ( 1931) looked for 

but did not detect gold in the for owing minerals: allanite, alvite (variety of zircon), andalusite, 1aragonite, beryl, brewster~te, bronzite, 
TABLE 3.-Analyses of gold in minerrals made since 1954 

[Minerals containing higher amounts of gold are listed in table 1] 

Mineral and loeality 

Arsenolamprite, As 

Germany, Thuringia 

Iron, (Fe, Ni) 

U.S.S.R., Sikhote-Alin' _________ _ 

Arsenopyrite, FeAsS 

U.S.S.R., Central Chukotki ______ _ 

Germany, Thuringia 

Chalcopyrite, CuFeSs 

U.S.S.R., Almalyk 

Germany, Thuringia 

Cobaltite, CoAsS 

Germany, Thuringia 

Galena, PbS 

U.S.S.R: 

Central Chukotki _____________ _ 

Almalyk ----------------------

Germany, Thuringia 

Molybdenite, MoSs 

Germany, Thuringia 

Pyrite, FeSt 

East Greenland ------·------------ U.S.S.R: 

Almalyk ----------------------

Do 

Central Chukotki --------------

Gennany, Thuringia ____________ _ 

Gold 

(ppm) 

5 

1.15 

200 

.5 

.22 

5 

5 

13 

3 

.02 

.01 

.02 

.016 

3.5 

10 

.2 

Remarks 

Elements 

Silver, 1 ppm. Spectographic analysis. 

One sample of meteorite. In troilite. 

0.067 ppm Au. Neutron activation 

analysis. 

Snlftdes 

Samples from veins and ore minerals. 

Silver, 15 ppm. Spectrographic analysis. 

Chalcopyrite is the chief "concentrator" but pyrite is ·the chief 

"carrier." Content in parts per 

million of Pd, 0.21, Pt, 0.02, Ag, 

0.02. Analyses by fire assay followed by spectrographic. 

Pd, 0.2 ppm, Ag 10-3percent. Spectrographic analysis. 

Silver, 20 ppm. Spectrographic analysis. 

Silver, 450 ppm. Pd, 0.032 ppm. 

Analyses by fire assay followed 

by spectrographic. 

Silver, 29-100 ppm. Spectrographic 

analysis. 

Content in parts per million of: Ru, 

0.03, Rh, 0.4, Pd, 0.6, Pt, 0.4, Ag. 

>lo-s percent. 

Content in parts per million of: Ag, 

60, Se, 40, and Te, 16. Pyrite is 

the chief "carrier" but chalcopyrite is the chief "concentrator" of 

gold. 

Silver, 36 ppm, Pt, 0.014 ppm. Analyses by fire assay followed by 

spectrographic. 

Samples from veins and ore minerals. 

Silver, 5 ppm. Spectrographic analysis. 

10 

Fischer (1958-59). 

ShcheJ·bakov and 

Perczhogin 

(19fi4). 

Sidoro":r (1966). 

Fischer (1958-59). 

Badalc~r (1965) 

and Badalov and 

Tere.khovich 

(196~). 

Fische~ (1958-59). 

Do. 

Sidoro,. (1966). 

Badalo"• and 

Tere1rhovich 

(1961i). 

Fische1· (1958-59). 

Do. 

Vincen-4: and 

Crocket (1960). 

Badal on ( 1965). 

Badalo"r and 

Terel~hovich 

(196f). 

Sidorov (1966). 

Fischer (1958-59). 
TABLE 3.-Analyses of gold in minerals made since 1954-Continued 

Mineral and locality 

Pyrrhotite, Fet-xS 

East Greenland _________________ _ 

U.S.S.R., Central Chukotki ______ _ 

Sphalerite, (Zn, Fe) S 

U.S.S.R., Central Chukotki ______ _ 

Stibnite, SlnSa 

U.S.S.R., Central Chukotki ______ _ 

Germany, Thuringia ____________ _ 

Troilite, FeS 

United States: 

Canyon Diablo, Ariz 

Sardis, Ga --------------------

U.S.S.R., Sikhote-Alin' __________ _ 

Ullmanite, NiSbS 

Germany, Thuringia 

Tetrahedrite, Cu12Sb4S1a 

Germany, Thuringia 

Magnetite, FeaO• 

United States, Helena, Mont -----

U.S.S.R., Altai-Sayan folded belt (?) 

Pyrolusite, Mn02 

Germany, Thuringia 

Quartz, Si02 

U.S.S.R.: 

Central Chukotki _____________ _ 

Altai and Transbaikal _________ _ 

Altai-Sayan folded belt ( ?) ____ _ 

Gold 

(ppm) Remarks 

Sulfid-<1ontinued 

0.003 

2 

500 

20 

.9 

.10 

.23 

.67 

1 

0.02 

0.037 

.048 

Analyses by neutron activation ___ _ 

Samples from veins and ore minerals. 

_ _______________ do 

________________ do ______________ _ 

Silver, 2 ppm. Spectrographic analysis. 

One sample of meteorite. Analysis 

by neutron activation. 

One sample of meteorite found in 

rocks of Miocene age. Analysis 

by neutron activation. 

One sample of meteorite. The iron 

part of this meteorite contained 

1.15 ppm Au. 

Silver, 10 ppm. SpectrogTaphic analysis. 

Sulfosalts 

Silver, 20-100 ppm. 

graphic analysis. 

Oxides 

SpectroForty-four samples from the 

Marysville quartz diorite stock, 

20 miles northwest of Helena, 

Mont. Fifty-one analyses made 

of these samples which ranged 

in gold from 0.003 to 0.329 ppm. 

Analyses by m~utron activation. 

Seven samples. Analyses by neutron activation. 

Silver, 3 ppm. Spectrographic analysis. 

2 Samples from veins and ore minerals. 

.0008 Analyses by neutron activation. 

.011 Analysis by neutron activation. 

Nine samples. 

11 

:B~ference 

Vince:-1t and 

Cro~ket (1960). 

Sidorov (1966). 

Do. 

Do. 

Fischer (1958-59). 

Baede.~ker (1967). 

Do. 

Shcherbakov and 

Per~hogin 

(19,~4). 

FisCher (1958-59). 

Do. 

Manwi and 

Brownlow 

(19r,7). 

Shche ... bakov and 

Per?.zhogin 

(19r,4). 

FisCher (1958-59). 

Sidorov (1966). 

AnosUn and 

Potap'yev 

(1966). 

Shche ... bakov and 

Per~hogin 

(19r,4). 
TABLE 3.-Analyses of gold in mi:nerals made since 1951,-Continued 

Mineral and loeality 

Quartz and feldspar 

United States, Helena, Mont _____ _ 

Wad, Mn oxide 

Germany, ThUringia 

Feldspars, AI ,silicates with K, Na, and 

Ca 

U.S.S.R., Altai-Sayan folded 

belt (?) ----------------------

Altai and Transbaikal -----------

Microcline, KAISiaOs 

U.S.S.R., S. E. Altai -------------

Amphiboles, hydrous silicates with 

chiefly Ca, Mg, Fe, AI, and N a 

U.S.S.R.: 

Altai-Sayan folded belt ( ?) 

Kuznetsk, Ala-Tau -------------

Hornblende, CatNa(MgFeH)4 AI, 

Fe +3Ti) a SisOn (O,OH) 2 

United States, Helena, Mont. ____ _ 

Pyroxene, silicates of Ca, Mg, Fe, and 

others 

U.S.S.R., Altai-Sayan folded 

belt (?) ----------------------

Tourmaline, complex silicate of B and 

AI 

U.S.S.R., Altai-Sayan folded 

belt (?) ----------------------

Muscovite, KAlt (AI Sis) Oto(OH)J 

U.S.S.R., Altai-Sayan folded 

belt (?) ----------------------

Gold 

(ppm) Remarks 

Oxides-Continued 

0.065 TEm samples from the Marysville 

quartz diorite stock, 20 miles 

northweSt of Helena, Mont. 

Twelve analyses made of these 

samples which ranged in gold 

from 0.006 to 0.176 ppm. Analyses by neutron activation. 

Silver, 5 ppm. Spectrographic analysis. 

Silicates 

0.0040 Twenty-seven samples. Analyses by 

neutron activation. 

.0003 Analysis by neutron activation. 

.018 One sample from a migmatite. Analysis by neutron activation. 

• 0059 Fourteen samples analyzed by 

neutron activation method. 

• 077 Two samples analyzed by neutron 

activation. 

.100 Thirty-seven samples from the 

Marysville quartz diorite stock, 

20 miles northwest of Helena, 

Mont. Forty-two analyses made 

of these samples which ranged 

in gold from 0.003 to 0.823 ppm. 

Analyses by neutron activation. 

.016 Eight samples analyzed by neutron 

activation. 

.012 Four samples analyzed by neutron 

activation. 

.0038 Seven samples analyzed by neutron 

activation. 

12 

R'!ferenee 

Mante~. and 

Brm..,Uow 

(1967). 

Fischer (1958-59). 

Shcher'-lakov and 

Perel;hogin 

(1964). 

Anoshi"' and 

Pota:o'yev 

(1966). 

Shcherhakov and 

Pere?.hogin 

(19M). 

Do • 

Do . 

Mantei and 

Brownlow 

(1967). 

Shcherbakov and 

Perezhogin 

(1964). 

Do. 

Do. 
TABLE 3.-Analyses of gold in minerals made since 1954-Continued 

:Mineral and locality 

Gold 

(ppm) Remarks Refnrenee 

Silicates-Continued 

Biotite, K(Mg, Fe)s(AlS6) Oto(OH)I 

United States, Helena, Mont _____ _ 0.076 Forty-four samples from the Mantei and 

Brownlow 

(1967). 

U.S.S.R., Altai-Sayan folded 

Marysville quartz diorite stock, 

20 miles northwest of Helena, 

Mont. Fifty-three analyses made 

of these samples which ranged 

in gold from 0.002 to 0.924 ppm. 

Analyses by neutron activation. 

belt (?) ---------------------- .0040 Eight samples analyzed by neutron 

activation. 

Sheher't'f-tkov and 

Perezhogin 

(1964). 

Altai --------------------------- • 0091 Three samples from granite which 

were analyzed by neutron activation. 

Do . 

Olivine, (Mg,Fe)sSi04 

U.S.S.R., Altai-Sayan folded 

belt (?) ---------------------- .014 Two samples analyzed by neutron Do. 

activation. 

Sphene, CaTiSiOs 

U.S.S.R., Altai-Sayan folded 

belt (?) ---------------------- .0039 Two samples analyzed by neutron Shcherl1.kov and 

Perexhogin 

(1964). 

cristobalite, daubreelite (from meteorites), diopside, epidote, euclase, garnet, gersdorffite, 

harmotome, hauerite, heulandite, hornblende, 

kaolin, lepidolite, leucite, malachite, malacon, 

molybandocker [ilsemannite], molybdosodalite, 

muscovite, nepheline, olivine, orpiment, orthoclase, pyroxene, rhodochrosite, rutile, serpentine, stibnite, tantalite, thalenite, and thortveitite. The lower limit of detection of the 

analytical method they used seems to be about 

10 ppb. Other specimens of some of these 

minerals analyzed by neutron activation methods also show less than 10 ppb Au (table 

3). 

Platinum exceeds gold in meteorites, as well 

as in metasilicate minerals and orthosilicate 

minerals. 

COMPOSITION AND THE FINENESS OF GOLD 

Samples of native gold from 48 places 

throughout the world have been analyzed for 

selected elements (Gay, 1963). The frequency 

of occurrence of 30 elements detected (in order 

of frequency) is as follows: 

activation. 

13 

Detected in 90-100 percent of 

the samples ------------------Ag, Cu, f'e 

Detected in 18.8-37.6 percent of 

the samples ------------------Ph, Ti, Al, Sb, Hg, 

V, Bi, Mn, Si, As, 

Sn 

Detected in 6.3-14.6 percent of 

the samples __________________ Mg, Ni, Ca, Zn, 

Pd, Pt, Te 

Detected in 2.1-4.2 percent of 

the samples __________________ B, Co, C1·, Mo, Cd, 

Rh, Sr, W, Zr 

It is probable that not all the elements in the foregoing list were looked for by most analysts. 

Warren and Thompson (1944) studied the 

composition of 66 samples of native Jr">ld, about 

75 percent of which originated ir Canada. 

All samples contained silver, copper~ and iron. 

The number of occurrences of the varous other 

elements in the gold were: titanium. 52~ mercury, 42: manganese, 40~ lead, 37; vanadium, 

28: tin, 22: antimony, 21; bismuth, 19r arsenic, 

17~ zinc, 1&, cadmium, 14, tellurium. 8: platinum, 3t and palladium, 2. Silver w".c; usually 

present in amounts exceeding 0.5 p~rcent and 
copper was usually present in amounts from 

0.1 percent to 0.5 percent. The remaining elements, when present in the gold, were usually 

in amo'Jnts of less than 1 percent. 

Wise (1964), in a study of binary alloys 

of gold, gives the various maximum high-temperature solid solubilities of elements in gold 

as follows: 

100 percent ____________________ Ag, Cu, Ni, Pd, Pt 

46 percent _--------------------Fe 

21.5---19 percent _______________ Cd, Cr, Hg 

13 percent --------------------- Zn 

10.9-7.7 percent _______________ Mn, Ta, Co, In 

5.2-1.2 percent ________________ V, Ga, Sn, Mg, AI, 

Ti, Ge 

<1 percent --------------------As. Bi, Ca, Mo, Pb, 

Pr, Rh, Sb, Th, 

Tl, U, and perhaps others. 

The fineness of gold, and especially its relation to the genesis of gold denosits. has been 

studied by numerous workers (Gay, 1963; Sundell, 1936; Mertie, 1940). Fineness refers to 

the ratio of gold to the sum of the gold plus 

the silver in the naturally occurring alloys 

and is defined as 1,000 times Au/(Au+Ag). 

Me:rtie (1940) noted that pure gold has not 

been found in nature, but that gold is always 

alloyed with silver and a small amount of 

the base metals such as iro.n and copper. The 

purest gold reported by Mertie was from the 

Great Boulder mine, in the Kalgoorlie district 

of Western Australia; it was 999.1 fine. Mertie 

concluded that fineness is rarely less than 600 

and is generally never less than 400, although 

Lincoln (1911) reported a fineness of 246 for 

· silver-gold alloys in some mafic igneous rocks. 

The color of gold in polished section is an 

index of its fineness, according to Eales (1961). 

Nearly pure gold has a golden color with a 

ruby tint. With increasing amounts of silver, 

the color changes to yellow and eventually 

becomes ~ pale silvery yellow color as in electrum. Others have noted color differences in 

gold due to variations in fineness (Mather, 

1937; Russell, 1929; Edwards, 1958). 

Boyle (1960), Ward (1958), and Lincoln 

(1911) have commented on the fineness of 

gold in different country rocks. Boyle thought 

that the fineness of gold in lode deposits reflected the nature of the country rock and 

14 

that this seemed to indicate that the deposits 

were formed by diffusion of gold and silver 

through the cou.ntry rock. For instance, in 

the Yellowknife district of Cans da, gold -in 

deposits in greenstone has a gold~silver ratio 

of 5:1 ( = fineness 833), whernas gold in 

quartz lenses in sedimentary rocks has a ratio 

of 3.5:1 ( = fineness 778). Ward observed 

that gold in some ore bodies in '\\~estern Australia that are genetically relatr1 to albite 

porphyry intrusives has a gold to silver ratio 

greater than 9:1 ( = fineness 9(1). Lincoln 

noted that the fineness of gold i~ higher in 

silicic igneous rocks than in maf~ varieties; 

gold in silicic igneous rocks aver? ~es 979 in 

fineness, that in intermediate typ~s 451, and 

that in mafic types 245. 

Native gold at the surface and in the oxidized 

zone of a mineral deposit is usuall: .. finer than 

is the native gold in the unoxidizei ore (Don, 

1898; Fisher, 1945; Colin, 1946; MacGregor, 

1928; Mackay, 1944; Mills, 1954. and Gay, 

1963). Below the oxidized zone, hc~~ever, gold 

fineness seems to be largely ind~pendent of 

depth (Gay, 1963). A small decr~ase in the 

fineness of gold with depth in the. Lily mine, 

Republic of South Africa, is reported by Anhaeusser (1966) and shown in 1able 4. On 

the other hand, average gold fine~ess in the 

Zwartkopje shoot in the Sheba mine, Republic of South Africa, increases with depth from 

the 14 level (about 910 fine) to 1he 26 level 

(about 950 fine) within a vertical distance 

of about 550 feet (Gay, 1964). 

TABLE 4.-Variations in fineness of gold with depth, 

Lily Mine, Transvaal, South Africa 

[After Anhaeusser, 1966] 

Depth 

in feet 

below 

2,600-foot 

datum Gold Silv·~r 

Level plane (percent) (percent·) Fineness 

70-foot ______ . _ ---- 200 

1 ----- ·--- ---·------ 260 

1% _ .. -------- -- - --- --- 340 

2-----------------. 420 

91.50 

91.15 

90."8 

89.04 

8.50 

8.85 

9 72 

10.96 

915 

911.5 

903 

890 

Gold fineness was noted by Gay (1963) to 

vary from east to west in some Witwatersrand 

deposits as follows: 865.8, 884.0, 870.6, 926.0, 

912.0, 924.0, and 970.0. Sharwood (1911) reports some lateral variation in fineness of bullion from mines in the Lead district, South 

Dakota; as shown in table 5, the range in 

fineness is small. 
TABLE 5.-Fineness, in percent, of mill bullion prior to 

1882 at the Homestake mine, South Dakota 

[Sharwood. 1911] 

Mine Gold 

Homestake ____________ 82.0 

Highland ______________ 83.0 Terra ______________ 82.5 

Deadwood ______ ------- 85.0 

De Smet -------------- 82.0 

Base Silver metal' Fineness 

17.0 

15.5 

16.0 

14.0 

17.0 

1.0 

1.5 

1.5 

1.0 

1.0 

828 

843 

838 

859 

828 

Lateral variation in fineness is shown by 

analyses of the bullion from nine representative mines in Gilpin County, Colo. (Collins, 

1902). During the period 1870 to 1880, the 

fineness ranged from mine to mine from 753 

to 897, and during the period 1880 to 1890, 

from 716 to 894. The average fineness of all 

the bullion from these mines changed little 

during the two periods; it was 799 for the 

first and 789 for the second. 

Eales (1961) studied the silver content of 

gold from four hydrothermal deposits in 

Southern Rhodesia. Gold that mineragraphic 

studies show to have crystallized early, and 

that is enclosed in chalcopyrite and sphalerite, 

contains more silver than does gold that crystallized later. 

The fineness of gold varies directly with 

particle size in some deposits and inversely 

with particle size in others (Gay, 1963). 

For ore deposits in general, the fineness 

of the contained gold increases as the grade of 

ore increases; (Eales, 1961; Lawn, 1924; Mac--

Gregor, 1928; and Mackay, 1944). 

Fisher ( 1950) concluded that fineness used 

with other criteria furnishes a sensitive and 

reliable guide to the relative temperature of 

ore formation, at least within the epithermal 

and the upper part of the mesothermal range 

of temperatures. The fineness of epithermal 

gold is from 500 to 700. Near the bottom 

of the epithermal zone (corresponding to the 

leptothermal zone of Graton, 1933), the fineness is about 700 and may be as much as 

800. The fineness of mesothermal gold varies 

from 750 to 900, with 850-870 being common. 

The fineness of hypothermal gold is always 

greater than 800. Fineness of 900 or more 

results from oxidation under conditions favoring the removal of silver. 

Gay (1963) observed that commonly the 

fineness of placer gold increases downstream 

from its so·Jrce. This increase is explained 

by leaching of the silver and redeposition of 

15 

the gold. Shcherbina (1956) explains that the 

high ratio of silver to gold, 37J\ (Mason, 

1952) in sea waters, compared to only about 

10 (Vinogradov, 1956) for the lith9sphere as 

a whole, is an indication of the gre~.ter mobility of silver. 

Mertie (1940) says that in sotro. Alaskan 

paystreaks the fineness of gold incre.q,ses downstream from its source, but in others the fineness changes either erratically or not at all. 

He cites an Alaskan placer gold d~posit that 

was derived from lodes in Tertiary quartz 

monzonite. The source lodes were being actively 

mined around 1940, and informat~0n on the 

fineness of both lode and placer gold indicates that the fineness does not increase progressively downstream. 

Fineness varies not only from gr8.in to grain 

but also w.jthin graillls (Gay. 1963). Some 

grains are finer in the center than on the 

surface (Head, 1935), although Er.les (1961) 

has noted the reverse. Gold extrac~ed by McConnell (1907) from the outer surface of a 

nugget assayed 60-70 parts per tho~lsand finer 

than gold from the inside of the rugget, and 

his findings have been cited as evidence that 

surface waters dissolve an appreciable amount 

of silver from alluvial gold. However, the difference could have been due to the original 

character of the primary lode gold or to surficial enrichment of the gold in the zone of 

oxidation before it was freed (Mertie, 1940). 

Very fine grained placer gold is u~ually finer 

than the coarse gold (Hite, 193~; Sundell, 

1936; Fisher, 1945; and Colin, 1~46). However, Mertie (1940) reports that in any one 

paystreak, and at any o.ne place in the paystreak, the reverse is usually true. 

REFERENCES CITED 

Anhaeusser, C. R., 1966, Supergene goH enrichment 

in the Barberton Mountain Land wth particular 

reference to the Lily Mine: Witwatersrand Univ. 

Econ. Geology Research Unit lnf. Circ. 29, 16 p. 

Anoshin, G. N., and Potap'yev, V. V., 1966, Gold in 

granites of the Kolyvan' (Altay) ard KhangilayShilinskiy (Transbaikalia) massifs (according to 

radioactivation analysis data): Geokhimiya, no. 9, 

p. 1070-1074 (in Russian). Translation in Geochemistry Internat., 1966, v. 3, no. 5, f· 850-854. 

Badalov, S. T., 1965, On the role of predominant 

components in the geochemistry of minor and rare 

elements of ore deposits: Geochemistry Internat., 

v.2, no. 5,p.857-860. 
Badalov, S. T., and Terekhovich, S. L., 1966, Geochemistry of elements of the Pt group in the 

Almalk ore region: Akad. N auk SSSR Doklady, 

v. 168, p. 1397-1399 (in Russian). 

Baedecker, P. A., 1967, The distribution of gold and 

iridium in meteoritic and terrestrial materials: 

U.S. Atomic Energy Comm. [Pub.] OR0-2670-

17, -and Ph. D. thesis, Kentucky Univ., 110 p. 

Boyle," R. W., 1960, The geology, geochemistry and 

origin of the gold deposits of the Yellowknife 

district: Canada Geol. Survey Mem. 310, 193 p. 

Cloke, P. L., and Kelly, W. C., 1964, Solubility of 

gold under inorganic supergene conditions : Econ. 

Geology, v. 59, p. 25,9-270. 

Colin, L. L., 1946, Gold fineness in relation to geology; 

considerations of the Macequece field [Mozambique]: S.outh Africa Mining and Eng. Jour., v. 

57, pt. I, p. 279-283. 

Collins, G. E., 1902, The relative distribution of gold 

and silver values in the ores of Gilpin County, 

Colorado: Inst. Mining and Metallurgy Trans. 

(London) v. 12, p. 480-499. 

Don, J. R., 1898, The genesis of certain auriferous 

lodes: Am. Inst. •Mining Engineers Trans., v. 27, 

564-668. 

Eales, H. V., 1961, Fineness of gold in some Southern 

Rhodesian gold mines: Inst. Mining and Metallurgy Trans., Bull. no. 660, v. 71, p. 49-73. 

Edwards, A. B., 1958, The mineral composition of 

the Maude and Yellow Girl gold ore, Glen Wills, 

Victoria: F. L. Stillwell Anniversary Volume 

Melbourne, Australasian Inst. Mining and Metallurgy p. 105-132. 

Fischer, Karl-Wilhelm, 1958-59, Zur Geochemie der 

Edelmetalle. Spektralanalytische Untersuchungen 

and Thiiringer Gesteinen und Mineralien: Wiss. 

Zeitschr. Hochschule f. Architekur u. Bauwesen 

Weimar, v. 6, no. 2, p. 85-91. 

Fisher, N. H., 1945, The fineness of gold, with special 

reference to the Morobe gold field: Econ. Geology, 

v. 40, p. 449-495 and 537-563. 

1950, Application of gold· fineness to the 

search for ore: Australasian Inst. Mining and 

Metallurgy Proc. 156-157, p. 185-190. 

Friedrick, K., 1906, Untersuchungen iiber den Goldge.-

halt von Gebirgsproben and Solen deutscher 

Salzlagerstatten: Metallurgie, v. 3, no. 2, p. 627-

630. 

Gay, N. C., 1963, A review of the geochemical characteristics of gold in ore deposits: Witwatersrand 

Univ. Econ. Geology Research Unit Inf. Circ. 12, 

70p. 

1964, The composition of gold from the 

Barberton mountain land: Witwatersrand Univ. 

Econ. Geology Research Unit Inf. Circ. 19, 53 p. 

Goldschmidt, V. M., and Peters, Cl., 1932, Zur 

Geochemie des Edelmetalle: Gesell. Wiss. Gottingen, Nachr., Math-Phys. Kl. no. 4, p. 377-401. 

Goni, J ., Guillemin, C., and Sarcia, C., 1967, Geochemie de l'or exogime. Etude experimentale de 

la formation des dispersions colloidales d'or et 

16 

de leur stabilite: Mineralium Deposita, v. 1, p. 

259-268. 

Graton, L. C., 1933, The depth-zones in or~ deposition: 

Econ Geology, v. 28, p. 513-555. 

Head, R. E., 1935, Form and occurrence of gold in 

pyrite-coated gold: Canadian Minir~ Jour., v. 

56, (II), p. 517-521. 

Hegemann, Friedrich, and Leybold, Chr., 1954, 

Eine Methode zur quantitative sp~ktrochemischen Analyse von Pyrite: Zeitschr. Erzbergbau 

u. Metallhiittenwesen, v. 7, p. 108-113. 

Helgeson, H. C., and Garrels, R. M., 1968, Hydrothermal transport and deposition of gold: Econ. 

Geology, v. 63, p. 622-635. 

Hite, T. H., 1933, Fine gold and platinum of Snake 

River, Idaho: Econ Geology, v. 28, p, 256-265. 

Krauskopf, K. B., 1951, The solubility of gold: Econ. 

Geology, v. 46, p. 858-870. 

Lawn, J. G. E., 1924, Presidential add1·~ss on the 

subject of silver in Witwatersrand ores: Geol. 

Soc. South Africa Proc., v. 27, p. 19-31. 

Lincoln, R. C., 1911, Certain natural ass'leiations of 

gold: Econ. Geology, v. 6, p. 247-302. 

Liversidge, A., 1897, Presence of gold in natural 

saline deposits and marine plants: ~Tour. Chern. 

Soc., v. 71, p. 298-299. 

McConnell, R. G., 1907, Report on the gold values in 

the Klondike high-level gravels: Cz.nada Geol. 

Survey, no. 979, 134 p. 

MacGregor, A. M., 1928, The geology of the country 

around the Lonely Mine, Bubi Dis4:rict: Geol. 

Survey Southern Rhodesia Bull., no. 11, 96 p. 

Mackay, R. A. C., 1944, Purity of nativ~ gold as a 

criterion for secondary enrichme.nt: Econ. 

Geology, v. 39, p. 56-68. 

Mantei, E. J., and Brownlow, A. H., 1967, VariatiQn in gold content of minerals of the Marysville quartz diorite stock, Montana: Geoehim. et 

Cosmochim. Acta, v. 31, no. 2, p. 225-23L 

Mason, Brian, 1952, Principles of geocheirtstry: New 

York, John Wiley and Sons, 276 p. 

Mather, W. B., 1937, Geology and par,,genesis of 

gold ores of the Howey mine, Red Lal·~, Ontario: 

Econ. Geology, v. 32, p. 131-153. 

Mertie, J. B., Jr., 1940, Placer gold in Ala~ka: Washington Acad. Sci. Jour., v. 30, p. 93-124. 

Mills, J. W., 19'54. Vertical zoning at the O'Brien 

gold mine, Kewagama, Quebec: Econ. Geology, v. 

49, p. 423-430. 

Minguzzi, Carlo, 1947, Dosatura spettro:n-afica dell 

oro in piriti italiane: Soc. Toscana Sci. Nat. Atti., 

Mem., v. 54, p. 210-243. 

Noddack, Ida, and Noddack, Walter, 1931. Die Geochemie des Rheniums: Zeitschr. Phys. Chemie, v. 

154A, p. 207-244. 

Ottemann, J., and Augustithis, S. S., 1967, ~chemistry 

and origin of "platinum-nuggets" in lateritic 

covers from ultrabasic rocks and b~rbirites of 

W. Ethiopia: Mineralium Deposita, v. 1, p. 269-

277. 
Palache, Charles, Berman, Harry, and Frondel, 

Clifford, 1944, Dana's System of Mineralogy: 7th 

ed., New York, John Wiley and Sons, v. 1, 834 p. 

Ramdohr, Paul, 1967, The wide-spread paragenesis of 

ore minerals originating during serpentinization: 

Geologiya Rudnykh Mestorozhdenii, no. 2, p. 32-

43 (in Russian). 

Ringwood, A. E., 1955, The principles governing 

trace element distribution during magmatic 

crystallization: Geochim. et Cosmochim. Acta, v. 

7,p. 189-202,242-254. 

Russell, A., 1929, On the occurrence of native 

gold at Hope's Nose, Torquay, Devonshire: 

Mineralog. Mag., v. 22, p. 159-162. 

Schneiderhohn, H., 1929, The mineragraphy and spectrography of the sulfide platinum ores of the 

Bushveld complex, chap. XVII, p. 206-246, in 

Wagner, P. A., The platinum deposits and mines 

of South Africa: Edinburgh and London, Oliver 

and Boyd. 

Schneiderhohn, H., and Moritz, H., 1931, Spektrographische Untersuchungen iiber die Verteilung 

der Platinmetalle in den Mineralien der siidafrikanischen Plantinlagerstiitten: Festschr. d. 

Platinschmelze G. Siebert, Hanau, p. 257-287. 

Schwartz, G. M., 1944, Host minerals of native gold: 

Econ. Geology v. 39, p. 371-411. 

Sharwood, W. T., 1911, Analyses of rocks and 

minerals from Homestake mine, Lead, South 

Dakota: Econ. Geology, v. 6, p. 729-789. 

17 

Shcherbakov, Yu. G., and Perezhogin, G. A., 1964, 

Geochemistry of gold: Geochemistry Internat., 

no. 3, p. 489-496. 

Shcherbina, V. V., 1956, The geochemical significance 

of the quantitative silver/gold ratio: Geokhimiya, 

no. 3, p. 65-83 (in Russian). 

Sidorov, A. A., 1966, Gold-silver mine¥alization of 

Central Chukotki: Akad. N auk SSfR Magadan. 

Severo-Vostoch. kompleks. N auchno.-Issled. Inst. 

Trudy, vyp. 14, 146 p. (in Russian). 

Sundell, I. G., 1936, Fineness and co"'llposition of 

alluvial gold from the Ivalojoki, Finnish Lapland: Comm. Geol. Finlande, Bull. no. 115, p. 

155-1.60. 

Terziev, G., 1966, Kost.ovite, a gold-coiJper telluride 

from Bulgaria: Am. ;Mineralogist, v. 51, p. 29-36. 

Vincent, E. A., and Crocket, J. H., 1961), Studies on 

the geochemistry of gold. I. The distribution of 

gold in rocks and minerals of the Skaergaard 

intrusion, East Greenland: Geochim. et Cosmochim. Acta, v. 18, p. 130-142. 

Vinogradov, A. P., 1956, Regularity of distribution 

of chemical elements in the earth'f crust: Geokhimiya, translation, no. 1, p. 1-43. 

Ward, H. J., 1958, Albite porphyries as a guide to 

gold ore: Econ. Geology, v. 53, p. 754-756. 

Warren, H. V., and Thompson, R. M., 1944, Minor 

elements in gold: Econ. Geology, v. 39, p. 457-

471. 

Wise, E. M., 1964, Gold: recovery, properties, and 

applications: New York, D. Van }ITostrand, Co., 

Inc., 367 p.