Cerussite, PbCO3 (Lead Carbonate), is often called white lead ore. Its properties are nearly identical to Witherite, but the mineral has the highest specific gravity of any Carbonate. It typically forms as a weathering product of other primary lead ores, especially Galena.

Description: This is an interesting supergene assemblage where white Cerrusite crystals have been partially overgrown by a thin blanket of pale blue Chrysocolla. The crystals are really quite small, but under magnification can be seen to form pyramids. The contrast between the white and the blue is most attractive.

Location: Whytes Cleugh, Wanlockhead, Scotland.