Black crystals of the extremely rare thallium mineral rebulite in a matrix of orpiment and realgar from a new find in Shimen, China (Jiepaiyu, Shimen County, Hunan Province), a locality that was only previously known for orpiment and realgar crystals. Rebulite has only ben found in two localities worldwide. Specimen analyzed by SEM. — Photo: David Hospital · CC BY-SA 4.0
Rebulite
Rebulite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Tl₅Sb₅As₈S₂₂.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: specific gravity 4.81; Brownish red streak; Submetallic to metallic. R1 –R2: n.d luster.
IMA symbol Reb, IMA status: approved, named in 1982.
Found in a hydrothermal As–Tl deposit.
It is found associated with Simonite, TlHgAsS3 (christite or routhierite), realgar.
The mineral was named to honor a Slovenian geologist or mining engineer named Rebula, who discovered the mineral.