Laurite
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 | |
|---|---|
|  | |
| General | |
| Category | Sulfide mineral | 
| Formula (repeating unit) | RuS2 | 
| Strunz classification | 2.EB.05a | 
| Crystal system | Cubic | 
| Crystal class | Diploidal (m3) H-M symbol: (P 2/m 3) | 
| Space group | Pa3 | 
| Unit cell | a = 5.61 Å; Z = 4 | 
| Structure | |
|   Crystal structure of Laurite S Ru | |
| Identification | |
| Color | Iron-black; white to gray or bluish in polished section | 
| Crystal habit | As octahedral, cubic, and pyritohedral crystals or as rounded grains and inclusions | 
| Cleavage | Perfect on {111} | 
| Fracture | Subconchoidal | 
| Tenacity | Brittle | 
| Mohs scale hardness | 7.5 | 
| Luster | Metallic | 
| Streak | Dark gray | 
| Diaphaneity | Opaque | 
| Specific gravity | 6.43 | 
| Density | 6.43 g/cm3 (Measured) 6.39 g/cm3 (Calculated) | 
| Optical properties | Isotropic and opaque | 
| References | [1][2][3] | 
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
    
- Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Laurite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 14 March 2022.
- Laurite, Mindat.org
- "Laurite Mineral Data". Webmineral.com.
- 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. Retrieved 20 June 2022.
- 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.