This sample of bayldonite is displayed in the Smithsonian Museum of Natural History. Bayldonite is an oxide (arsenate) which contains copper, zinc and lead and arsenic with the composition (CuZn)₃Pb(AsO₄)₂(OH)₂.H₂O. This sample is about 5x6 cm and is from Tsumeb, Namibia. The bayldonite is formed with olivenite and adamite.