Chemistry:Laurite

From HandWiki
Laurite
Laurite.jpg
General
CategorySulfide mineral
Formula
(repeating unit)
RuS2
Strunz classification2.EB.05a
Crystal systemCubic
Crystal classDiploidal (m3)
H-M symbol: (P 2/m 3)
Space groupPa3
Unit cella = 5.61 Å; Z = 4
Structure
Kristallstruktur Pyrit.png
Crystal structure of Laurite
     S      Ru
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
|re|er}}Metallic
StreakDark gray
DiaphaneityOpaque
Specific gravity6.43
Density6.43 g/cm3 (Measured) 6.39 g/cm3 (Calculated)
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 it's been found in many localities worldwide, it is extremely rare.

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] The sulfur is present as the disulfide ion, S2−
2
, so the ruthenium is in the Ru(II) oxidation state.[4]

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]

Synthetic RuS2 is a highly active catalyst for hydrodesulfurization.[5]

References

  1. 1.0 1.1 Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Laurite". Mineral Data Publishing. http://www.handbookofmineralogy.org/pdfs/laurite.pdf. 
  2. 2.0 2.1 2.2 Laurite, MinDat.org, http://www.mindat.org/show.php?id=2344 
  3. "Laurite Mineral Data". http://www.webmineral.com/data/Laurite.shtml. 
  4. Cocco, R.A.; Tatarchuk, B.J. (1989). "Effects of presulfidization on the selectivity and surface structure of ruthenium catalysts". Langmuir 5 (6): 1309–1315. doi:10.1021/la00090a005. https://pubs.acs.org/doi/pdf/10.1021/la00090a005. Retrieved 20 June 2022. 
  5. Chianelli, R. R.; Berhault, G.; Raybaud, P.; Kasztelan, S.; Hafner, J.; Toulhoat, H. (2002). "Periodic Trends in Hydrodesulfurization: in Support of the Sabatier Principle". Appl. Catal., A 227 (1–2): 83–96. doi:10.1016/S0926-860X(01)00924-3.