Realgar
Image: Tomwsulcer (CC0)
Mineral NameRealgar
Chemical FormulaAs₄S₄
Mohs Hardness1.5
Crystal Systemmonoclinic
Lusterresinous
Streak Colororange-red
Cleavagegood on {010}
Fractureconchoidal
Specific Gravity3.5
Colorsred, orange-red
Transparencytransparent
Type LocalityHunan Province (China), Baia Sprie (Romania), Nevada (USA)
Mineral Groupsulfides
Usescollector, historical pigment
Associated Mineralsorpiment, arsenopyrite, galena, pyrite, cinnabar
Rarityuncommon
Description
Realgar is a striking bright red to orange-red mineral, often forming prismatic crystals or granular masses with a resinous luster. Its vibrant color makes it a distinctive specimen.
Geological Context
Realgar forms in low-temperature hydrothermal veins, hot spring deposits, and as a volcanic sublimate. It is typically found in environments rich in arsenic and sulfur.
