This vivianite is from the Tomokoni Adit in the Canutillos Mine in the Machacamarlin District, Cornelio Saavedra Region, Potosi Department, Bolivia. This region contains 49 different mineral species and this audit is mined exclusively for the recovery of vivianite specimens. It is a phosphate containing the elements A, X, O and H. This specimen consists of large vivianite crystals on a sandstone matrix. The crystals have a rich green color and vitreous luster. When viewed from the side the crystals have a translucent emerald like appearance. This piece measures 2 1/2 x1 1/2 x 1 1/2 inches or 64 x 38 x 38 mm.