Jump to content
Wikipedia The Free Encyclopedia

Nagyágite

From Wikipedia, the free encyclopedia
Sulfide mineral
Nagyágite
Nagyágite from Nagyág (Săcărâmb), Romania (image width: 1.5 mm)
General
CategorySulfosalt mineral
Formula Pb
5
Au(Te,Sb)}
4
S
(5–8)
[1] or AuPb(Sb,Bi)Te
(2–3)
S
6
[2] or (Te,Au)Pb(Pb,Sb)S2[3]
IMA symbol Ngy[4]
Strunz classification 2.HB.20a
Dana classification 02.11.10.01
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group P21/m
Identification
ColourBlackish lead-grey; pale grey in polished section
Crystal habit Tabular crystals (often bent), also massive granular, pseudotetragonal
Twinning Crossed twin lamellae observed on (001) sections
Cleavage Perfect on {010}, excellent on {101}
Fracture Hackly
Tenacity Flexible, slightly malleable
Mohs scale hardness1.5
Lustre Metallic, bright on fresh cleavage
Streak Blackish lead-grey
Diaphaneity Opaque
Specific gravity 7.35–7.49
Pleochroism Weak
References[1] [2] [3]

Nagyágite (Pb
5
Au(Te,Sb)
4
S
(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

[edit ]
  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.
Wikimedia Commons has media related to Nagyágite .
Stub icon

This article about a specific sulfide mineral is a stub. You can help Wikipedia by expanding it.

AltStyle によって変換されたページ (->オリジナル) /