Realgar
Image: James St. John (CC BY 2.0)
Mineral NameRealgar
Chemical FormulaAsS
Mohs Hardness1.5
Crystal Systemmonoclinic
Lusterresinous
Streak Colororange-red
Cleavagegood on {010}, poor on {100}
Fractureconchoidal
Specific Gravity3.5
Colorsred, orange-red, yellowish-red
Transparencytransparent
Type LocalityShimen Mine, Hunan Province, China
Mineral Groupsulfides
Usespigment, arsenic ore, collector's item
Associated Mineralsorpiment, arsenopyrite, stibnite, cinnabar, pyrite, galena, calcite, barite
Rarityuncommon
Description
This specimen displays vibrant, deep orange-red to red crystalline masses with a distinct resinous to greasy luster, forming intricate clusters.
Geological Context
Realgar typically forms in low-temperature hydrothermal veins, hot spring deposits, and as a volcanic sublimate. It is often found in association with other arsenic-bearing minerals in ore deposits.
