Bayldonite is a rare mineral composed of copper, lead, and arsenate, with the chemical formula PbCu₃(AsO₄)₂(OH)₂. It belongs to the arsenate mineral group and crystallizes in the monoclinic crystal system. The mineral was first discovered in England and is named after John Bayldon, an English metallurgist. Bayldonite is typically found in shades of green, bluish-green, or yellowish-green. Its color is mainly due to the presence of copper within its structure. The mineral usually occurs in massive or microcrystalline forms rather than well-formed crystals, although small crystals can sometimes be observed. It has a vitreous to resinous luster and is generally translucent to opaque.it relatively soft and prone to scratches. Its specific gravity ranges between 5.3 and 5.5, reflecting its heavy metal content, particularly lead.