This specimen is from the Refugio Mine in Choix, Mun.de Choix, Sinaloa, Mexico. This mine is famous for the smithsonite specimens recovered and offered on the market by Benny Fenn. Smithsonite is a carbonate mineral containing the elements Zn, C, and O. It is found in the oxidation zones of zinc ore deposits. This locale produced ( no longer in operation ) a wide variety of colors and multiple color combinations of the mineral. This specimen is a mound-like formation of mixed shades of blue-green of smithsonite. It is translucent at the surface under bright light and it has a vitreous luster. This piece measures 2 3/4 x 1 13/16 x 1 1/4 inches or 70 x 46 x 32 mm.