Nagyágite

Sulfide mineral
(Te,Au)Pb(Pb,Sb)S2[3]IMA symbolNgy[4]Strunz classification2.HB.20aDana classification02.11.10.01Crystal systemMonoclinicCrystal classPrismatic (2/m)
(same H-M symbol)Space groupP21/mIdentificationColourBlackish lead-grey; pale grey in polished sectionCrystal habitTabular crystals (often bent), also massive granular, pseudotetragonalTwinningCrossed twin lamellae observed on (001) sectionsCleavagePerfect on {010}, excellent on {101}FractureHacklyTenacityFlexible, slightly malleableMohs scale hardness1.5LustreMetallic, bright on fresh cleavageStreakBlackish lead-greyDiaphaneityOpaqueSpecific gravity7.35–7.49PleochroismWeakReferences[1][2][3]

Nagyágite (Pb
5Au(Te,Sb)
4S
(5–8)) is a rare sulfide mineral with known occurrence associated with gold ores. Nagyágite crystals are opaque, monoclinic and dark grey to black coloured.

It was first described in 1845 for an occurrence at the type locality of the Nagyág mine, Săcărâmb, Hunedoara County, Romania.[1][2]

It occurs in gold–tellurium epithermal hydrothermal veins. Minerals associated with nagyágite include: altaite, petzite, stutzite, sylvanite, tellurantimony, coloradoite, krennerite, native arsenic, native gold, proustite, rhodochrosite, arsenopyrite, sphalerite, tetrahedrite, calaverite, tellurobismuthite, galena and pyrite.[3]

References

  1. ^ a b c Nagyágite, Mindat.org, retrieved 6 August 2022
  2. ^ a b c Barthelmy, David (2014). "Nagyagite Mineral Data". Webmineral.com. Retrieved 6 August 2022.
  3. ^ a b c Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Nagyágite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 6 August 2022.
  4. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
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