Orange red crystals of the rare mineral sarabauite from the type locality on a contrasting matrix of wollastonite-2M. Sarabauite has only been found in two close localities in Borneo. From: Sarabau Mine, Bau, Sarawak, Borneo, Malaysia. — Photo: David Hospital · CC BY-SA 4.0
Sarabauite
A red monoclinic calcium antimony oxysulfide.
Intro adapted from Wikipedia (CC BY-SA).
Sarabauite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Sb₄S₆·CaSb₆O₁₀.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: Mohs hardness 4; specific gravity 4.8; Orange streak; Resinous luster; optically biaxial.
IMA symbol Sbu, IMA status: approved, named in 1976.
Found in hydrothermal mineral deposits, deposited at high temperature.
It is found associated with Stibnite, sénarmontite, wollastonite, calcite, quartz (Sarabau mine, Malaysia).
The name refers to its occurrence in the Sarabau mine, Malaysia.