The rectangular mustard-colored wulfenite crystals contrast significantly against the dark and olive-green mimetite.
Wulfenite and mimetite often form together as both minerals are leaden-based.
Wulfenite was discovered in the late 18th century by Austrian mineralogist Ignaz von Born, who gave it the name plumbum spatosum flavo pellucidum, meaning "yellow, glasslike lead ore." Franz Xavier von Wulfen later renamed the mineral wulfenite in 1845 when he discovered a deposit of it in Bleiberg, Austria. Today, the mineral can be found in Mexico, Arizona and China.
Mimetite is a secondary mineral formed as a product of the oxidation of galena (lead sulfide) and arsenopyrite (iron arsenic sulfide). Mimetite is so-named because it “mimics” the appearance of other lead-based minerals like pyromorphite.
Type: Wulfenite-Mimetite
Locality: San Juan Poniente, Ojuela Mine, Mapimí, Mun. de Mapimí, Durango, Mexico
Size: 2.5 x 1.75 x 1.13 inches
Weight: 2.5 oz.