American Mineralogist, Volume 64, pages 432435, 1979

Ore mineralsin a polymetallicdeposit of Primorye,U.S.S.R.

V. T. KnzecHENKo,V. M. CHUBnRov,I. M. RouaNENKo The Far East Geologicql Institute Academy of Sciencesof the U.S.S.R.

L. N. Vlnlsov eNp G. V. Bnsovn Instit.ute of Ore Deposits, Petrography, Mineralogy and Geochemistry Academy of Sciencesof the U.S.S.R.

Abstract

Mn-metasomatitesformed by a complex of rare silicates(bustamite, manganoan diopside, pyroxmangite, rhodonite, pyrosmalite, knebelite, spessartine) are widespread in a poly- metallicdeposit of South Primorye (SovietFar East).Pb-Zn oreswere formed by replacement of manganous metasomatites.As well as the usual sulfides(, sphalerite, pyrrhotite, stibnite, arsenopyrite,chalcopyrite, and others), sulfoantimonitesof lead (amesonite and boulangerite), , and miargyrite, they contain some very rare minerals, such as meneghinite,dyscrasite, diaphorite, gudmundite, antimony, aurostibite, argentian tetrahe- drite, and freibergite. A new sulfoantimonite of lead and silver, AgPbrSbuSrr.r,a new sulfide of iron and silver,(Fe,Ag),S, and an unusual(antimonian) variety of freegold, Auo,uSboou, are also found in the ores. The presenceof this complex of rare and new minerals of manganous metasomatite and ore indicatesthe specificconditions of formation of the deposit.

Introduction and miargyrite, they contain a number of very rare dyscrasite,diaphorite, This depositof South Primorye is in the zone of the minerals,such as meneghinite, ,frei- main Sikhote-Alin synclinorium and occurs in Early gudmundite, antimony, argentian which are describedbelow. Cretaceous sandstonesand siltstones.The deposit bergite,and new minerals consistsof veinlike bodiesof Mn- and Fe-metasoma- The minerals were analyzed by JXA-5A micro- tites formed by a complex of rare silicates.The Mn- probe at the laboratory of physico-chemicalmethods metasomatite body is zoned upward: bustamite * of the Geological Institute of the Far East Science manganoan diopside + pgoxmangite + rhodonite Center, Academy of Sciencesof the U.S.S.R. Micro- (pyrosmalite) - knebelite. probe analysesof mineralswere carried out at 20 kV. During the formation of the polymetallic mineral- Standardsused for this analysiswere: synthetic chal- ization the above-mentioned minerals were replaced costibite (for Cu,Sb,S); synthetic chalcostibite and by rare hydrous Mn-silicates, namely amphiboles, bismuthinite (S); pyrite (Fe); arsenopyrite(Fe,As); stilpnomelane,and hisingerite.A zonality is also ob- galena(Pb); metallic silver (Ag); ZnSe (Zn); metallic served in the distribution of amphiboles, which is gold (Au). The standard errors of the analysesare causedby the primary composition (zonality) of the within t5 percent. Concentrations were calculated manganousmetasomatites: calcic ones are observed by the computer program of Afonin et al. (1971). on lower levels(manganoan actinolites) and calcium- Corrections for absorption, atomic number, and poor ones(dannemorite) on middle and upper levels. characteristicand continuousfluorescence were used. The Pb-Zn ores were formed by replacement of Reflectance measurements were conducted using manganous metasomatites.As well as the usual sul- silicon, carborundum, and pyrite as standards.X-ray fides (galena, sphalerite, pyrrhotite, stibnite, arse- powder diffraction data were obtainedwith a 57.3mm nopyrite, chalcopyrite,and others), sulfoantimonites diameter camera and unfiltered Fe radiation on of lead fiamesonite and boulangerite),pyrargyrite, grains removed from polished sections' 0003-004x / 79 / 0304-0432$02.00 432 KAZACHENKO ET AL: ORE MINERALS 433

Table l. Powder data of new sulfoantimonite of lead and silver

d (A)

(3.882) 2 2.358 3. 7r8 3 (2.226) 3.536 4 2 .098* 3.430* 5 2.O27 3.360 5 1. 886

3.276 I 1.808 3.118 I l, .'760 2.9'75* 10 1 708* 2.432 9 1. 330* 2 .449 1

*The reflectance of galena

New lead-silver sulfoantimonite A new lead-silversulfoantimonite was found in the ore. This mineral, which forms fine intergrowthswith galena,freibergite, jamesonite, and carbonate(Fig. I ) has been studied by microscopeand microprobe in more than twenty grains. In most of thesegrains it is the main phase. Fig. l. Intergrowthsof the new lead-silversulfoantimonite (l) A microprobe analysisof this mineral gave(weight with galena(2), freibergite(3), carbonate(4), andjamesonite (5). percent):Pb 56.81;Ag 3.45;Sb 22.59;S 18.69;sum 101.54.Recalculation of this analysis to 16 cations yields the formula Agr.ooPbr.rrSbu.ouSrrru. Ideal for- mulas are AgPbrSb.Srr.uor Ag2Pbr8Sb12Ss?. This composition (18 in Fig. 2) liesalong a trend of previously known silver-antimony-lead sulfosalts. The powder-diffractiondata are given in Table l. In polished section, this sulfosalt resemblesthe others of this series.It is especiallysimilar to james- onite, with which it occurs. Both exhibit approxi- mately the sameanisotropism and bireflectance(Fig. 3), and both are characterizedby two directions of -longitudinal perfect and transverseindis- -L, tinct. This sulfosaltis slightly greenishin comparison ,:+L to galenabut lessintense than the greenof freibergite. Oriented inclusionsof galenaare common along the cleavagesof the sulfosalt(Fig. I but less \----*o--^r., ---, ) common in the accompanyingjamesonite. -T*-r_ ----\ Freibergite occurs as rare intergrowths and thin veinletswithin the sulfo- - _:.19^ \ __ salt. The freibergite is characterized by the presence of inclusions of a Mn- and Fe-bearing carbonate sb Pb which is not presentin the other phases.It contains Fig 2. Ag-Sb-Pb diagram for sulfoantimonites.Crosses snow 16.0-30.6weight per cent Ag. ..brongniardite," lead-silver sulfoantimonites: (l ) Ag,S.PbS.Sb,S.; (2) diaphorite, l.5Ag,S.2pbS.l.5Sb,S,;(3) New silver-iron sulfide freieslebenite, 0.5AgrS PbS.0.5Sb,Sr; (4) andorite. A new sulfide of iron and silver, (Fe,Ag)"S, was 0.5Ag,S PbS. I .55bzS,;(5) ramdohrire, 0.5Ag,S. 2pbS. l.55b,S.; found in a carbonate-richportion (6) fizelyite,Ag,S . 5PbS.45b,S,; (7) owyheeite,Ag,S . 5pbS. 3SbzSs; of the ore, where it (8) "teremkovite," AgrS 7PbS.4Sb,Sr;(9) new lead-silversulfoan- is accompaniedby pyrrhotite, sphalerite,antimony, limonite, 0.5AgrS.9PbS.3Sb,Sr.Circles show sulfoantimonitesof and meneghinite.Microprobe analysisindicates that lead. this mineral contains 10.50to 22.62 weight percent 434 KAZACHENKOET AL.: ORE MINERALS

R,%

Rfi$s Itp

t00 500 600 700 .i,nm

Fig. 3. Reflectanceof (l) sulfoantimonite of lead and silver; (2) semseyite(Vialsov, 1973). silverand 47 .44 to 54.51weight percent iron, which is pyrrhotite, miargyrite,and argentiantetrahedrite in equivalentto FeorrAgo.rrSr.oo. This compositionand carbonate,sometimes as a border along grainsof an X-ray diffraction pattern and optical properties aurostibite.The reflectanceof this phase(Fig. 5) is (Fig. a) are very similarto thoseof pyrrhotiteand considerablyless than that of pure gold and has a suggestthat this phaseis an argentianpyrrhotite. maximumat about650nm. This phasetarnished rapidly when exposedto air, Theaurostibite of thisdeposit has a compositionof with the developmentof a reddishto violetfilm. Auo.roSbr.,o(Au41.27, Sb 59.77 weight percent), which is considerablymore antimonianthan most gold Antimonian known occurrences.The aurostibiteis white with a Antimonian gold has also been found in the slight pinkish tint in reflectedlight. Whereasmost carbonateore. This gold, of composition(weight reported aurostibiteoccurs as a secondaryreaction percent)Au 98.08,Sb 3.17(Auo.ruSbo.ou), occurs as rim betweengold and stibnite,this aurostibiteis ad- inclusions with meneghinite,sphalerite, galena, mixed with gold, meneghinite,miargyrite, and argen- tian tetrahedriteand appearsto be primary. R,% R'%

90 80 70 60

30 20 t0 2s#1,16 0 i,nm 400 s00 600 ?oo |{)0 500 500 ?00 Fig. 4. Reflectanceof ( I ) sulfide of iron and silver; (2) hexagonal Fig. 5. Reflectance of (l) antimonian gold; (2) antimony-free pyrrhotite (Vialsov, 1973). gold (Vialsov, 1973). KAZACHENKO ET AL.: ORE MINERALS 435

Table2. Powderdata of ( I ) rheiron-silver sulfide, and (2) the main nousmetasomatite and ore indicatesunusual condi- reflections pyrrhotite of accordingto Berryand Thompson(t962, tionsof formationof this deposit. p. 60)

Acknowledgments d (A) The authors are indebted to coworkers ofthe Far East Geologi- cal Institute of the Academy of Sciencesof the U.S.S.R., S. A. 2.990 2 3 .00 Korenbaum and S. A. Scheka,and to (2.9L6) 2 M. G. Dobrovolskaya of 2.643 9 2.65 6 Institute of Ore Deposits, Petrography, Mineralogy and Geochem- istry of the U.S.S.R. I Academy of Sciencesfor advice and notes and 2.060 l0 2.08 10 discussionof this article. I-723 3 L.72A 5 References Argentiantetrahedrite (freibergite) Afonin,V. P., L. A. Perfilyevaand Yu G. Lavrentyev(1971) Program for the computer calculation of element The concentration oresof the PrimoryeDeposit are alsocharac- by X-ray fluorescence microanalysis of the various chemical terizedby admixturesof argentiantetrahedrite, with composition specimens.(in Russian) Slberian GeochemicalInsti- up to 30.6weight percent silver, miargyrite, with 35.g tute Year Book, 1971, Irkutsk,398-400. powder weight percent silver, and meneghinite,which con- Berry, L. G. and R. M. Thompson (1962) X-ray Dara for Ore Minerals: the Peacock Atlas. Geol. Soc. tainsno silver.This assemblage provides information Am. Mem. 85. Chvileva, T. N. (1973) Mineralogical characteristic and tliagnostic concerningthe partitioningof silver among anti- of sulfoantimonites of lead. (in Russian) Nauka Publishing mony-bearingsulfosalts. House, Moscow. Nativeantimony, dyscrasite, gudmundite, and an Vialsov, L. N. (1973) The reflectanceof ore minerals. (in Russian) unusualvariety of arsenopyrite(containing Sb) are IGEM, Acad. i/aak SSSR, Moscow. rareminerals present in this deposit. presence The of Manuscript receiued, February 15, 1978; the complex of rareand new minerals in the manea- accepted lor publication, October 20, 1978.