C anadian M ineral:ogist
Vol. 18, pp. 165-171 (1980)

SWEDEN:
AREA,BERGSLAGEN,
cOBALTMINERALSIN THEHALLEFORS
PARACOSTIBITE'
GOSTTBITE'OFNEW OCCURRENCESNISBITEAND COBALTIANULLMANNITE
M.A. ZAKRZEWSKI, E.A.J. BURKE eNp H.W. NUGTEREN*'
Institute of Earth Sciences,Free University,De Boelelaan1085'
1801HV Amsterdam,The Netherlands
lagen, a Precambrian metallogenic province'nJrgjtagen is well known for its more thanZ,OOOiron deposits and more than 200 baseCostibite, paracostibite, nisbite and cobaltian ull'mannite are found associated for the first time in
metal deposits,predominantly of the polymetallic
de- Ag-Pb--Zn({u)
the small Gruv&sen and Gettin Pb Zn{u-Agtype. The Falun, Sala, Garposits, western Bergslagen, central Sweden. A review penberg and Kaveltorp mines are representatlveof the Co minerals in the Bergslagen province is bf ttrere sulfide deposits. Practically all ore
given. They were probably formed by remobilization
deposits are connected with folded' metamor'of cobalt from older sulfides by hydrothermalphbsed volcanic rocks of rhyolitic composition
solutions during emplacement of late orogenic or(in Sweden called hiilleflintas whete finely cryspostorogenic granites.
talline, and leptites where more coarse grained).
Keywords: costibite, paracostibite, nisbite, cobaltian These rocks and the associatedmetasedimentaryullmannite. cobalt ores, electron-microprobe anal- units were intruded and surrounded by graniterysis, Bergslagen, Sweden.
of at least two generations during the l80G2000 Ma Svecofennian folding. The geology of
SovrlreRe
the Bergslagen province has been summarized
by Magnusson(1970) and Grip (1978).
A Gruvisen et Geton, deux petits gisements deCobalt ores were mined in this region as a
Pb-Zn-Cu-Ag situ6s dans le Bergslagen occidental
by-product of the copper ores. Betweel.lAlZ(Subde centrale), on trouve pour la premiEre fois
aira ISOS about 310 metric tons of metallic Co
I'association costibite, paracostibite, nisbite et ullmannite cobaltifdre. Aprbs r6examen des min6raux were extractedfrom seven mines (Fig. 1): thede cobalt du Bergslagen, nous proposons comme Gladhammar mine produced 89.6Vo of the total,
m6canisme g6n6tigue une remobilisation hydrotherYena 8.7/o and Tunaberg l.3Va; O.4Vo came
male du Co de sulfures anciens pendant la mise en from the HAkansboda, Atvidaberg, Los andplace de granites tardifs, voire post-orog6niques.
Riddarhyttan mines (Tegengren 1924). Minor
amounti of Co minerals were also found in
Cfraduit Par la R6daction)
several other polymetallic ore deposits.
M ots-clis : costibite, paracostibite, nisbite, ullmannite
Cobaltite is the main source of Co in all thecobaltifire, minerai de cobalt, analyse !r la mimentioned above; it also occurs in small
mines
crosonde, Bergslagen. SuEde.
quantities in the Utii, Brodd and Ingelsby mines'.;Smaltite'chloanthite" ( = skutterudite) is deINtnooucttoN
scribed from Vena and Los, but Welin (1965)
showed that the museum specimens from Los
Investigations within the,framework of a curconsist of cobaltite. Linnaeite is noted in Glad'rent project on the petrology and ore geology
hammar. where it occurs with cobaltite' carof the Hlllefors area of central Sweden (Fig.
rollite and bravoite. and in Riddarhyttan with
1) led to the discovery of the minerals costibite,
cobaltite" skutterudite and several cerium minparacostibite and nisbite in the Gruv6sen anderals. Glaucodot is known from Hlkansboda inGetdn deposits, and of cobaltian ullmannite inperfect crystals that occur with cobaltite
large,-Cu-Zn-Pb
the Getiin deposit. These two mines are smallores. Co-bearing arsenopyrite (7.9
inoccurrences in western BergsPb--Zn{u-Agwt. Va Co) has been describ€d from the Los
mine (Welin 1965). Safflorite occurs in Tuna*Present address: U.N.D.P.. B.P. 836. Yaound6, berg.
In connection with the presenceof nisbite in
Cameroun.
AssrRAcr

165

166

THE

CANADIAN MINERALOGIST

Ftc. 1. Geological map of the Hbllefors area, simplifieil after Magnusson (1925) and Sundius (1923),
with location of examples of cobalt mineralization. Inset shows the location of cobalt-bearing deposits incentral Sweden and situation of the Hiillefors area. (l) Late orogenic and postorogenic granites, (2)Svecofennian synorogenic granites, (3) slates and greywackes, (4) greenstones, (5) leptites and hiilleflintas, (6) limestones and dolomites.

the Hiillefors area, it is interesting to note theNi minerals of central Sweden. Breithauptite
was found in Tunaberg (Odman 1933) withrammelsbergite, nickeline, pentlandite, cobaltite
and safflorite, in the Sv[rdsjii Zn-Pb-Cu minewith Ag, Bi and Mo minerals, and in Kaveltorp
in Cu-Pb-Zn ores with Bi, Mo, Ag, Au andAs minerals. Gersdorffite occurs in the Los mine,and nickeline in Sala.Pentlanditeis the common
mineral in Ni mines, where it occurs with pyrrhotite and chalcopyrite.
Co MrNsneuzATroNs rN THq Hilnrrons

AnEe

The discovery of the CoSbS phases in theGetiin and Gruv&sen mines started a search for
Co minerals in about 80 other base-metal deposits in the Hiillefors area. Cobalt minerals were
found in only six deposits, in addition to two
other localities (Nordmark and G6sborn) described by Magnusson (1925). Their locations
are marked on the geologicalmap (Fig. 1). All
these Co mineralizations are small and without
any economic value, but they constitute an important phenomenon in discussionsof genesisin

the Bergslagendistrict. Table I presents a summary of the ore-mineral paragenesesof these
deposits.
The Get0n mine (Fig. 2) is situated on asmall island 8 km east of Filipstad in the western flank of the Saxi syncline. A magnetitebearing skarn was developed between the dolomite and leptite unitb that form the border of acentral limestone dome. The sulfides either occur in the magnetite ore or form separatebodies.
A cordierite-gedrite quartzite accompanies themagnetite and sulfide ores in the northern partof the island. This ore-bearing quartzite, which
also occurs in other Bergslagensulfide deposits,
can be compared with a similar unit in the
Falun mine. Production started in 174O,initiallyfor iron and later for Cu, Pb and Ag. During
short periods of activity before 1918, about
50,000 tons of magnetite ore were extracted,
along with ores containing 650 tons 'of Pb, 50
tons of Cu and 40O kg of Ag. As the dumps
from the last period of production are relatively
rich in sphalerite, it is probable that 3'00-600
tgns of Zn werc also present in the sulfidic
ores.

COBALTMINERALSFROM

HALLEFORS.

SWBDENt67

M1NERALIZATION'
IN CO-BEARINGASSEMBLAGESMINERAL
The Gruv6sen deposit (Fig. 3) is located TABLE1. OBE
HALLEFORS
AREA
about 4 km east of Get6n in the Saxi syncline,
which involves slates, greywackes, greenstones,
1234567891011
Mineraldolomites and limestones surrounded by leptites. 0old+++
The mineralization occurs in the dolomites Si lver+largentm
flanked by sterile limestones, suggestingthat the Al+{+
Bi smuth
Antimony
carbonates form a local anticline (Magnusson
+
t
+
tat
lena
1925). The anticline is truncated to the south by Ga+as e l e n i a ng a l e n a+++++++
post-Svecofenniangranites (1700 Ma: Welin etl,lurtzi te+t
al. 1977). Ore was excavatedfrom seven mines Troi l ite
during the sixteenth and seventeenth centuries; Pyrrhotite+++++
Pyri te+rc asi temore recent exploitation took place from 1906 l',la+tMackinawitet+a
to 1.9'17,and numerous pits and dumps are still Cubanite
++++
tt++t
Chalcopyri tein evidence from this operation. The estimated CovelI i te+t+
Stanni teproduction was about 500 tons of Pb:Zn:Cu in Acanthi+
teithe proportion 11:9:1. The richest deposit was Hessite
Tetradynite
the Ling mine in the central part of the car- Bismuthinite++++tebonate -dome. Judging by the location of the Molybdeni++tArsenopyriteate0udmundi
dumps, it is assumed that the central storage Cobaltite
t++t+tpoint of the ores was close to the northern 0ersdorffi te++bishaft, the Kung Karla mine. There are two types Costi teParacostibi teof ore: (1) massive sphalerite with pyrrhotite, C o b a l t i a nu l l m a n n i t etchalcopyrite and galena and (2) light-colored N i s b i t e
Brei thaupti tediopside skarn with rich disseminationsof chal- Nickeli ne
Skutterudite
copyrite, molybdenite and native bismuth.
saffl ori te
The Finnfalls mine is a small excavation 2 Tetrahedrite+++
Pyrargyri te
km south of Gruvisen. About 250 tons of Cu
fosal tPb-Sb-sul
B i- s u l f o s a lt
ore were produced, of two types: (1) rich
Cosali tedisseminationsof pyrrhotite and chalcopyrite in Galenobismutitent++greenstone and (2) disseminations with native l4agnetite+t
Hematitet+Ilmenitebismuth, molyMenite and chalcopyrite, minRuti leeralogically very similar to the Gruvlsen mine Goethi teff{}
Cassiterite(Table 1). The trace-element contents of galena scheel+i teand sphalerite from both localities are also very
1 . 6 1 g y l s e n ,L B n gm i n e ( s p e c . 1 2 f ) i 2 . G r u v 9 s e nT, o r s k e b a cm
k ine;
similar.
3 . G r u v S s e nD, r e s f a l l m i n e ; 4 . G e t b n ,s t o r a s i l v e r n i n e ( s p e c .
56C3); 5. Getiin, Koppar+ Norra minei^6. F'innfallsi 7. Nordnark
The Nord iron mine oscurs in the Finnshyt- (Magnusson,1925); 8. Nord minei 9. GHsborn(l'lagnusson,1925);
k ,e r s . c o m . ) .
1 0 . S i k f o r s ; 1 1 . .S u n d s u d d e( sn. l . l a e s s c h a l c pteberg field, 4 km north of Filipstad. The ironores occur in skarns and leptite rocks surroundedby the Filipstad granite. According to Magnusson (1925) the ore consistsof magnetite with ered by S. Maesschalck (pers. comm. 1'979).
accessory pyrrhotite and pyrite; the most in- The geology of the Sikfors mine resemblesthatteresting feature, however, is the occurrence of of the Finnfalls mine. Cobaltite and skutterudite
native bismuth. The latter mineral uras found are associatedwith pyrite, pyrrhotite and chalin samplds from the dumps, as microscopic in- copyrite, which occur together with quartz,
clusions in a Co mineralization containing co- chlorite and calcite in gteenstone and in finebaltite, cobaltian pyrite, linnaeite--corrollite and grained leptite.
clinosafflorite (Burke & Zakrzewski in prep.).
In the Nordmark mine sulfides occur as disDsscntpttoN or (Co,Nr)-S"-S P'nesrs
seminations in the Mn-bearing carbonate dome
Costibite has previously been described fromassociatedwith the main magnetite skarn ores.
The ore minerals, as described by Magnusson Broken Hill, New South Wales, Australia(Cabri et al. l97Db), paracostibite from the Red(1925), are listed in Table 1.
In the Gisborn mine a small cobaltite and Lake area, Ontario (Cabri et al. 1'97Oe) andbismuthinite mineralization was noticed by Mag- from the Guangdong province, China (Anonnusson (1925) in the magnetite -ores of the ymous 1976), nisbite also from the Red Lake
Anders Pers shaft. In Sundsudden.a small man- area (Cabri et al.. l97}c) and from the Festivalganesemine, disseminatedcobaltite was discov- noe Cu-Sn mine in the Magadan district,
f

168

THE

CANADIAN

MINERALOGIST

Frc. 2. Geological map of Getiin island (after Magnusson 1925) and location of mines. (1) Cordierite-gedrite quartzite, (2) lE>tite, (3) skarn,(4) iron ore, (5) limestone, (6) dolomite.
Flc. 3. Geological map of Gruvisen (after Magnusson 1925) and locationof mines. (1) Postorogenic granite, (2) slate, (3) spilitic greenstone,(4) greywacke, (5) massive greenstone, (6) limestone, (7) dolomite'

U.S.S.R. (Kachalovskaya& Kukoev 1973), andcobaltian ullmannite from Broken Hill (Cabri
et al. 1970a) and from Espeland, Norway (Naiket al. 1976). The present study reports the firstoccurrence in which the four minerals are foundtogether.
The small grain-size and the fine intergrowths
shown by these minerals prohibited the extraction of powder for X-ray-diffraction patterns;
thus, the identification of the (Co,Ni)-Sb-S
TABLE2. ELECTR0N-!4ICRoPRoBE
ANALYSES
0F Co- ANDNi-lillNERALSFROI4THEHATLEFORS
AREA
Spec.

l4ineral

374
622E
12,15
37A
56C3

Cobaltite3),.2 1.2
Cobaltite
27.7 4.2
17.9
N is b it e
skutterudi te18.6 0.9
Cobaltlanu l l m a n n i t e1 1 . 0 1 4 . 4
Costibite
25.6 2,4
Costibite
24.2 2,3
Costibite
25.6 1.8
Costibite
25.9 1.6
Paracostibite 23.2 3,1

56C3
r2f
t2f
r2f
r2f

Co

Ni

Fe

Sb

As

S

Total

2.4 47.7 19.3 101.8
2.5 44.8 19.2 98.4
74.2
92,1r
1.1 7 7. 9 98.5
2.3
0.8
2.0
0.6
0.3
1.5

52.7
56.8
55.0
56,6
56.1
56.1

0.3
0.3
0.3
0.4
0.2

15.7 99.3rt
14.7 100.6
15.0 98.8
14.4 99.3
14.6 98.9
14.5 98.6

r smi-quantitative analysisi lw total dueto small grain size!t includes 3.2 vt, % Pb from adjacent galena
analyses 6re reported ln reight r.
3 7 A- S i k f o r s i 6 2 2 E- s u n d s u d d e nl 2i J 5 - G r u v d s e nD^ r e s s f a l l s
n i n e i 5 6 C 3- G e t i i n ,S t o r a s i l v e r m i n e ; l 2 f - G r u v x s e nL, d n gm i n e .

phasesis based on electron-microprobe analyses
Z; and on the comparison of their
itutt"
optical properties with those described by Cabriei at. (1gzoa, b, c). Electron-microproh analyses were performed with a Cambridge Instruments Geoscan (equipped with a LINK energydispersive system) and Microscan 9. Naturaland synthetic compounds were used as standards'
Appaient concentrations were ZAF-correctedwith a modified Springer (1967) program andwith the Microscan 9 on-line ZAF program.
In the Gruv&sen deposit, intergrowths of
costibite and paracostibite (Figs. 4A and 48)
attain maximum dimensions of 40 x 40 pm, andalways occur on the contacts between chalcopyrite and native bisrnuth (see Table I for asummary of the mineral assemblage).The sompositions of both minerals are identical; electronmicroprobe traverses across the intergrowths
failed to show any differences. It is easy torecognize the minerals optically becauseof theirintergrowths. In oil immersion costibite showsa very weak reflection-pleochroism, grey-whitewith a bluish tint to grey-white with a brownish
tint. The anisotropy is distinct, somewhat
stronger than for chalcopyrite, with reddish-coBALT

MTNERALS FROM

HALLEFORS,SWEDENr69

brown and dark-grey polarization colors (withexactly crossed nicols), or orange and bluishcolors (nicols slightly uncrossed). In contrast.
paracostibite has a somewhat higher reflectanceand a more distinct reflection-pleochroism,
grey-white with a slight bluish tint (in thisposition almost the same as costibite) to greywhite with a pinkish tint (distinctly lighter thancostibite). The anisotropy is distinct, somewhat
stronger than for costibite, with the same polarization colors but with more pronounced tints.
Cobaltite (Fig. A) has a distinctly higher reflectance; costibite and paracostibite have amore bluish color in comparisogr.The anisotropy of costibite is weaker than that of cobaltite,
but paracostibite is more anisotropic than cobaltite. The polishing hardnessesof costibite andparacostibite are similar, higher than for chalcopyrite and lower than for cobaltite. The replacement of paracostibite by costibite (Fig. 4)
is in agreement with the suggestion by Cabri
et al. (l970b) that costibite is the lower temperature polymorph.
Nisbite occurs as small grains (maximum
diameter 4 pm) at the contacts between galena
and pyrrhotite grains. The mineral is white,shows a reflectance higher than all other phases
except native bismuth, and has a very weakreflection-pleochroism and anisotropy, much
weaker than for costibite. The polishing hardness is higher than for pyrrhotite. The occurrence of nisbite with pyrrhotite is also characteristic of the Red Lake (cabri et al. 1970c)
and Festivalnoe (Materikov 1977) deposits, inwhich it is further associatedwith chalcopyrite,
galena, arsenopyrite, tetrahedrite and breithauptite. Ullmannite and native bismuth are alsopresent in the Festivalnoe mine (Kachalovskaya& Kukoev 1973).
The identification of the (Co,Ni)-Sb-S phasesin the Gettin deposit is more difficult becauseof
the much smaller grain-size(Fig. aC). Costibite,
paracostibite, cobaltian ullmannite and gersdorffite occur as small inclusions in galena. The
optical properties of the CoSbS phases are thesame as in the Gruvlsen deposit. Cobaltian ullmannite"with Col (Co * Ni) = 43.2 (Table 2),
is greyo without pinkish or bluish tints, andisotropic; the reflectance is slightly higher thanfor costibite, but lower than for paracostibite,in agreementwith the data given by Cabri et al.
Frc. 4. Textural relations of Co and Ni minerals(1970b). A small grain of gersdorffite (2 p,m)from Gruv&sen (A, B: spec. 12f)' and Getiin
is white and isotropic. with a reflectance slightly(C: spec. 56C3). Drawings after microphotohigher than for paracostibite and cobaltian ullcraphs. Abbreviations: Bi native bismuth, Cb
mannite. The cobaltian ullmannite grains concobaltite, Cs costibite, Gn galena, Gf gersdorffite,
Ns nisbite, Pc paracostibite, Sp sphalerite, Ul
tain small speCks(1 pm) of a white. weakly
cobaltian ullmannite; black is gangue.
anisotropic mineral with a much higher reflect-

l7O

THE

cANADIAN

MINERALOGIST

paracostibite derived their Sb content from native bismuth or galena. The Co was probably
derived from chalcopyrite. The well-known preference of cobalt for chalcopyrite and pyrite,
Tns OccURRENcE oF Co MTNSRALS
and that of nickel for pyrrhotite (Cambel &N BsncslecsN
Jarkovsky' 1969), are demonstrated by the presField investigations and microscopic data in- ence of the Co phases'at contacts with chalcodicate the occurrence of two types of sulfide pyrite, and by the presence of nisbite at pyrmineralization in the polymetallic ores of rhotite contacts, resPectivelY.
The relative rarity of costibite and paracostibwestern Bergslagen. The older pyrrhotitepyrite-galena-sphalerite-chalcopyrite-arsenopy- ite compared with cobaltite is due to tworite mineralization may be regarded as belong- factors: (1) a relatively low concentration of
ing to the ooFaluntype", according to the classi' Co, leading to a general paucity of Co minfication of Magnusson (1970). The younger erals, and (2) the relatively high concentration
molybdenite-native bismuth-chalcopyrite(-stan- of As. In most Bergslagen Co deposits cobalnite) mineralization may be compared with the tite was the only Co mineral to form, provided"Yxsjiiberg-Hdrkentype" of Magnusson(1970). that the Co atoms did not stay trapped in pyrite
Discussion of the genesis of the Falun-type or chalcopyrite. The Sb-bearing phases could
mineralization is strongly influenced by the pro- only crystallize if. no more As was available.
posal of magnesiummetasomatismdevelopedby
The many Mo-W and Bi mineralizations inGeijer (1917, 1964) and Magnusson (1925, Bergslagen frequently occur in a spatial rela1970). According to this theory, the ore de- tionship with the late orogenic granite, but only
posits are introduced into the leptite complex in a few deposits is Co present in this para'by solutions driven from the synkinematic older genesis, suggesting that the granite could notgranites. These solutions would also be respon- have been the source of this metal. The distri
sible for the formation of the cordierite-gedrite- bution of Co minerals in the Hiillefors area
bearing quartzite that frequently ac'companies indicates two other possibilities: (1) remobilizathe sulfides. Koark (1962) suggestedthat the tion of cobalt from other sulfides of the older
ores \rere formed syngenetically, together with Falun type and (2) remobilization of cobalt
the volcano-sedimentaryrocks, their sourcebeing from greenstones.fn both cases cobalt would
volcanic exhalations or solutions. In this case, have been leached from chalcopyrite or pyrite,
the cordierite-gedrite rocks would be the result probably by hydlothermal solutions associatedof metamorphism of these volcano-sedimentary with the late orogenic or postorogenic granites.
deposits in a later stage. The Yxsjiiberg-Hdrken
type of mineralization is apparently related to
ACKNowl-EDGEMENTS
the late orogenic Svecofennian palingenetic graBoliden Metall AB kindly gave accessto theirnites and pegmatites (Magnusson 1970, Hiibner
1971, Ohlsson 1979). The ore minerals are material from the Bergslagen area. Professor
molybdenite, scheelite, chalcopyrite, native bis- Oen Ing Soen (University of Amsterdam) andmuth, sometimeswith bornite, sphalerite, allanite Dr. U. Wiklander (Geological Survey ofand fluorite. At Gruvlsen, the CoSbS minerals Sweden) are thanked for the helpful discussions
and for the specimens. Electron-microprobe
were formed in this type of mineralization.
Microscopic observations show that the os- facilities were trnovided by the Free University
currence of CoSbS phases is restricted to the and the WACOM, a working group for analcontacts between chalcopyrite and native bis- ytical geochemistry subsidized by the Nethermuth (Figs. 4A,B); in the Getbn examples,they lands Organization for the Advancement of
occur only at tlte contacts of galena with chal- Pure Research(mIO). Dr. C. Kieft (WACOM)
copyrite (Fig. C). Microprobe analysesof native carried out some of the analYses.
bismuth from Gruvisen show an Sb content
of 0.3 wt. /o in occtJnencesdevoid of Sb minRnrBneNcgs
erals, but under the detection limit (0.02 wt.
(1976): The crystal structureof para%) if Sb minerals are present. Similarly, in ANoNvltous
costibite. Sci. Geol. Sinica 1976, 227'234 (inpolished sections from Getiin containing CoSbS
Chinesewith English abstr.).
phases and native antimony, the Sb content ofgalena is below the detection limit, whereas in Cesnr, L,J., Hennrs, D.C., Srrwenr, J.M. & Rowr.eNo,J.F. (1970a): Willyamite redefined.Proc.
other sections galena contains 0.02-0.13 wt. 7oAust. Inst, Mining Metall.233, 95-100.
Sb. These observationssuggestthat costibite andance; it was determined as nisbite with the helpof electron-microprobe traverses across the
Sxains.

COBALTMINERALSFROM

HALLEFORS.

SWEDEN

171__,_,(1970b): Costib_&_(1970): The origin of the iron ores inite (CoSbS), a new mineral from Broken Hill.
central Sweden and the history of their altera,
N.S.W., Australia. Amer. Mineral. 55, lO-17,
tions. ,Syer. Geol. Unders, Ser, C 643.
_,_,
(1970c): para_ Mernnrrov, M.P. (1977): The Festivalnoe deposlt.
&_
costibite (CoSbS) and nisbite (Nisbr), new minIn Ore Deposits of the U.S.S.R. III (V.I. Smirerals from the Red Lake area, Ontario, Canada.
nov, ed.). Pitman, New York.
Can, Mineral. L0, 232-246,
Ceunnr., B. & Jemovsry', J. (1969): Geochemistryol Pyrrhotite ol Various Genetic?ypes.Komenskl Univ., Bratislava.
Gtt,rrn, P, (1917): Falutraktens berggrund ochmalmfyndigheter. ,Syer. Geol. (Inders, Ser, C
275.
-:(1964): On the origin of the Falun typeof sulfide mineralization. Geol. F6ren, Stoikholm F6rh.86,3-27,

Nex, M.S., GuFFrN, W.L. & Cennr, L.J. (1976):(Co,Ni)SbS
phases andargentianboulangerite in galena from Espeland, Norway.
Norsk Geol. Tidsskr. 56, 449454.

6ovex, O. ( 1933) : Erzmikroskopische Untersuchung der Sulfiderze von Kaveitorp in Mittelschweden. Geol, Fiiren. Stockholm Fbrh. 55, 563-

6rt.

OHLssoN, L.-G. (1979): Tungsten occurrences incentral Sweden, Econ. Geol. 74, 1012-1034.

Gryl-, E. (1978): CentralSweden(Bergslagen).
tr
SpnncER, G. (1967): Die Berechnung von Korrekturen ftr die quantitative Elektronenstrahl\lineral Depositsof Europe.l. NorthwesiEurope(S.H.U. Bowie, A. Kvalheim & H.W. Haslam,
Mikroanalyse. Fortschr, Mineral. 45, LO3-124.
eds.). Inst. Mining Metall., London.
SuNoIus, N. (1923): Grythyttef?iltets geologi. ,iver.
HiinNnn, H. (1971): Molybdenumand tungstenocGeol. Unders. Ser. C 3t2.
currencesin Sweden.Sver. Geol, tJnders. Ser.
TEceNcnnN, F.R. (1924): Sveriges iidlare malmer
Ca 46.
och bergverk Sver. Geol. Unders, Ser, Ca 17.

Kecserovsxeye, V.M. & Krxorv, V.A. (1973):
WnLtN, E. (1965): Two occurrences of uranium in
The first finding of nisbite in the U.S.S.R.iz, Investigationson Ore Mineralogy (M.S.
Sweden, The Los cobalt deposit and the iron ores
Bezsof the Viistervik area. Geol. Fdren. Stockholnt
mertnaya,ed.). Nauka, Moscow (in Russ.),
F6rh. 87, 492-508.
KoeRr, H.I. (1962): Zur Alterstellungund Entstehungder Srrlfiderzevom Typus Falun. GeoI. -,Gonurscnrv,
R. & Luxorcinpn,
P.H.
(1977): Rb--Sr dating of rocks in the Viirmland
Rundsch.52, 123-L46.
granite group in Sweden. Geol. Fdren, Stockholnt

IVf,acNussoN,
NJI. (1925): Berggrundeninom deF6rh, 99, 363-367.
centraladelarnaav FilipstadsBergslag.persbergs
Malmtraktsmalmfyndighetsr.Kungl. Kommerkollegium& Sver.Geol, (Jnders.Beskr,6vermineral- Received December 1.979, revised manuscript acfyndigheter2, l-231, 459464,
cepted, February 1980.