Cerussite crystals. Cerussite (lead carbonate) crystals are colourless or white with greyish tints and often form reticulated networks with 60 degree angles (as seen here). Cerussite occurs in the oxidation zones of lead deposits and is a minor lead ore. This sample is from Tsumeb, Namibia, and measures 7cm long. From Collection Royal Museum for Central Africa, Tervuren, Belgium.