U.S. Geological SurveyArsenic MineralsArsenic MineralsArsenic Minerals

USGS Arsenic Studies Group As Symbol

Arsenic Bearing Minerals

As Studies HomeReferencesMembership Directory

|| Arsenic | Realgar | Orpiment | Arsenopyrite | Löllingite | Enargite  ||

Arsenic Elemental Arsenic
Chemistry As, Elemental Arsenic
Color tin-white which quickly tarnishes to dark gray or black
Hardness 3 - 4
Specific Gravity 5.6 - 5.7
Crystal System hexagonal

 

Realgar RealgarRealgar
Chemistry AsS, Arsenic Sulfide
Color orange-red
Hardness 1.5-2
Specific Gravity 3.48
Crystal System monoclinic

 

Orpiment Orpiment Orpiment Orpiment Orpiment 
Chemistry As2S3, Arsenic Sulfide
Color lemon-yellow, orange, orange-brownish
Hardness 1.5-2
Specific Gravity 3.49
Crystal System monoclinic
Environment a sublimation product in fumaroles, and a byproduct of the decay of realgar.

 

Arsenopyrite Arsenopyrite Arsenopyrite Arsenopyrite 
Chemistry FeAsS, Iron Arsenic Sulfide
Color Silverish, whiteish-grey, metallic
Hardness 5.5-6
Specific Gravity 6.07
Crystal System monoclinic
Environment in sulfide ore deposits, common in medium to high temperature hydrothermal veins. Frequently in metamorphic deposits

 

Löllingite Löllingite  
Chemistry FeAs2, Iron Arsenide
Color silver white to gray
Hardness 5 - 5.5
Specific Gravity 7.1 - 7.5
Crystal System Orthorhombic

 

Enargite Enargite
Chemistry Cu3AsS4, Copper Arsenic Sulfide
Color gray to black
Hardness 3 - 3.5
Specific Gravity 4.4+
Crystal System orthorhombic

USGS Headquarters | Water Resources | Biological Resources | Geology | Mapping | USGS NRP | Help! | USGS Search | USGS Privacy Statement | Disclaimer   

URL: http://wwwbrr.cr.usgs.gov/usgs/Arsenic/minerals.htm
Created/Maintained: R. Blaine McCleskey; rbmccles@usgs.gov
Last Updated: 04/04/2008