These galena crystals are from Naica Mine in Naica, Mum.de Saucillo. Chihuahua, Mexico. This area consists of mineralized sills and dykes that contain over 95 different minerals. Over one dozen mines have exploited the deposits in the past but now most are incorporated into the Naica Mine. The ores processed in the mine are primarily for the recovery of gold, silver and other metals including lead. Galena Is a lead sulfide that contains the elements Pb and S. This piece consists of a matrix of crystalline galena and pyrite that is topped with cuboctahedral galena crystals and a cluster of calcite crystals. Many of the galena crystals are twinned. They have well defined habits, sharp edges and a bright mirror luster This piece measures 4 x 3 x 2 1/4 inches or 102 x 76 x 57 mm.