Bowieite
Bowieite is a rare sulfide mineral with the chemical formula (Rh,Ir,Pt)2S3. It is a member of the thiospinel group and is essentially a solid solution between rhodium sulfide (Rh2S3), iridium sulfide (Ir2S3), and platinum sulfide (Pt2S3).
Occurrence and Formation:
Bowieite is found in ultramafic rocks, particularly chromitites and platinum-group element (PGE) deposits. It typically forms as a secondary mineral, often associated with other PGE minerals like laurite, erlichmanite, and osmium-iridium alloys. Its formation is usually related to the alteration of primary PGE minerals by sulfur-rich fluids at elevated temperatures. Bowieite is a relatively rare mineral and is found in only a limited number of locations worldwide. Notable occurrences include deposits in Bushveld Complex, South Africa; the Ural Mountains, Russia; and Borneo.
Physical Properties:
Bowieite is opaque and has a metallic luster. Its color varies from light grey to greyish-white. It has a high density due to the presence of heavy platinum-group elements. The mineral exhibits a cubic crystal system, although it is often found as fine-grained aggregates or irregular grains. It is brittle with a distinct fracture.
Identification:
Bowieite is primarily identified through its chemical composition using techniques such as electron microprobe analysis. Its association with other PGE minerals and its occurrence in specific geological settings can also aid in its identification. X-ray diffraction (XRD) analysis can be used to confirm its crystal structure.
Etymology and History:
Bowieite was named in honor of Professor Stanley Bowie, a British economic geologist known for his contributions to the study of ore deposits.
Uses:
Due to its rarity and the presence of platinum-group elements, bowieite is of scientific interest. It serves as an indicator mineral for the presence of PGE mineralization and helps in understanding the genesis of PGE deposits. It has no significant industrial applications.