Bayldonite: Gemstone Information

The green lead–copper arsenate bayldonite Pb,Cu3(AsO4)2(OH)2 has sometimes been used ornamentally as somewhat metallic cabochons.Though members of the monoclinic system, crystals occur most commonly as mammillary crusts or powdery fine-grained masses. The hardness is 4.5, SG is 4.35 and the three RIs are 1.95, 1.97 and 1.99, biaxial positive. Bayldonite is found at Tsumeb in Namibia and in Cornwall,occurring in the oxidized zone of polymetallic deposits.