What is Crocoite?
Crocoite is a brilliant orange-red lead chromate celebrated for slender prismatic crystals, especially from Tasmania.
Mineralogy and structure
The reference formula is PbCrO4. Crocoite belongs to the sulfates and has a monoclinic crystal system. Crocoite is monoclinic and belongs to the monazite supergroup. Its intense colour and fragile crystals make it a classic cabinet specimen; lead and chromium require careful handling.
Colour and appearance
Typical colours include orange, orange-red, red, yellow. Crystal habit, lustre, transparency and matrix association are often as diagnostic as colour.
Formation and localities
Crocoite forms in or is associated with oxidised lead deposits where chromate-bearing fluids react with primary lead minerals. Important documented localities include Dundas in Tasmania, Berezovsk in Russia, Adelaide Mine in Australia and selected lead deposits.
Collecting and care
Crocoite is best kept as a labelled collector or reference specimen. Protect fragile crystals from impact and prolonged humidity changes. Lead-, arsenic-, chromium- and cobalt-bearing minerals should not be cut, ground or used in jewellery.
