Crocoite
Image: JJ Harrison (https://www.jjharrison.com.au/) (CC BY-SA 3.0)
Mineral NameCrocoite
Chemical FormulaPbCrO₄
Mohs Hardness2.5
Crystal Systemmonoclinic
Lusteradamantine
Streak Colororange-yellow
Cleavagedistinct on {110}
Fractureconchoidal to uneven
Specific Gravity6
Colorsorange-red, hyacinth-red, red
Transparencytranslucent to transparent
Type LocalityDundas, Tasmania
Mineral GroupChromate
Usescollector's mineral, minor ore of chromium
Associated Mineralsdundasite, cerussite, pyromorphite
Description
This specimen features vibrant orange-red, prismatic to acicular crystals of crocoite, often slender and elongated, growing on a white, botryoidal matrix of dundasite.
Geological Context
Crocoite is a secondary mineral that forms in the oxidized zone of lead deposits where lead-bearing solutions interact with chromium-bearing minerals. Dundasite, also a secondary mineral, forms in similar environments as a lead aluminum carbonate.
