What is Cerussite?
Cerussite is a lead carbonate known for bright adamantine lustre, high density and distinctive reticulated or twinned crystals.
Mineralogy and structure
The reference formula is PbCO3. Cerussite belongs to the carbonates and has a orthorhombic crystal system. Cerussite is orthorhombic and commonly forms contact twins that produce star-like or reticulated groups. Lead-bearing specimens are for display only and should not be cut or used in jewellery.
Colour and appearance
Typical colours include colourless, white, grey, pale yellow. Crystal habit, lustre, transparency and matrix association are often as diagnostic as colour.
Formation and localities
Cerussite forms in or is associated with oxidised zones of lead deposits where primary galena is altered by carbonate-rich groundwater. Important documented localities include Tsumeb in Namibia, Broken Hill in Australia, Sardinia, Morocco and many oxidised lead districts.
Collecting and care
Cerussite 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.
