Crocoite, lead chromate,
Formula PbCrO4
Crystal system: Monoclinic.(crystals are
typically long prismatic with striated faces,
often hollow.)
Hardness: 2.5 to 3
Density: 6.0 gms/cm3
Colour: Red or orange-red.
Streak: Orange-yellow.
Crocoite is a secondary mineral occurring in lead-rich deposits that also contain chromium bearing veins. It is often associated with other lead minerals such as anglesite, pyromorphite and cerussite. The best known location for Crocoite is Dundas in Tasmania.
The picture shows a matrix-free cluster of vermillion red crystals of crocoite, some showing the hollow crystals reported above. The specimen shown, with crystals up to 20mm long, comes from the Red Lead Mine, Dundas, Tasmania.