Laurite

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Chris.urs-o (talk | contribs) at 05:24, 9 November 2016. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Laurite
General
CategorySulfide mineral
Formula
(repeating unit)
RuS2
Strunz classification2.EB.05a
Crystal systemCubic
Crystal classDiploidal (m3)
H-M symbol: (2/m 3)
Space groupPa3
Unit cella = 5.61 Å; Z = 4
Identification
ColorIron-black; white to gray or bluish in polished section
Crystal habitAs octahedral, cubic, and pyritohedral crystals or as rounded grains and inclusions
CleavagePerfect on {111}
FractureSubconchoidal
TenacityBrittle
Mohs scale hardness7.5
LusterMetallic
StreakDark gray
DiaphaneityOpaque
Specific gravity6.43
Optical propertiesIsotropic and opaque
References[1][2][3]

Laurite is an opaque black, metallic ruthenium sulfide mineral with formula: RuS2. It crystallizes in the isometric system. It is in the pyrite structural group. Though rare, it occurs in many parts of the world.

Laurite has a Mohs hardness of 7.5 and a specific gravity of 6.43. It can contain osmium, rhodium, iridium, and iron substituting for the ruthenium.[2]

Discovery and occurrence

It was discovered in 1866 in Borneo, Malaysia and named for Laurie, the wife of Charles A. Joy, an American chemist.[2] It occurs in ultramafic magmatic cumulate deposits and sedimentary placer deposits derived from them. It occurs associated with cooperite, braggite, sperrylite, other minerals of the platinum group elements and chromite.[1]

References