Erlichmanite is the naturally occurring mineral form of osmium sulfide (OsS2). It is grey with a metallic luster, hardness around 5, and specific gravity about 9.[2] It is found in noble metal placer deposits.[3] Named for Jozef Erlichman, electron microprobe analyst at the NASA Ames Research Center.[4]

Erlichmanite
General
CategoryPyrite
Formula
(repeating unit)
OsS2
IMA symbolErl[1]
Strunz classification2/D.17-110
Dana classification2.12.1.16
Crystal systemIsometric
Crystal classDiploidal
Unit cell177.47 ų
Identification
Formula mass254.33gm
ColourGrey
Crystal habitPyritohedral crystals or grains
Mohs scale hardness4.5-5.5
LusterMetallic
DiaphaneityOpaque
Specific gravity8.28
Density8.28 g/cm3 (Measured), 9.59 g/cm3 (Calc)
PleochroismNon-pleochromic
Common impuritiesIridium, Rhodium, Ruthenium, Paladium

References

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  1. ^ 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.
  2. ^ "Erlichmanite".
  3. ^ "Erlichmanite Mineral Data".
  4. ^ http://www.handbookofmineralogy.org/pdfs/erlichmanite.pdf [bare URL PDF]