These mimetite crystals are from the Ojuela Mine in Mapimi, Durango, Mexico. There a over 115 different types of minerals in the mine including mimetite. It is an arsenate that contains the elements Pb, As, O and Cl. This stunning display piece consists of mound-like clusters of bright yellow mimetite crystals on a thin curved remnant limonite matrix. Each mound or spherical cluster contains dozens of rod shaped botryoidal formations of mimetite crystals. This piece measures 2 1/4 x 2 x 1 inches or 57 x 50 x 25 mm.