These fluorite crystals are from the Okorusu Mine in the Otjiwarongo Dist. of the Otjozondjupa Region of Namibia. This is an open pit operation that is most famous for the variety of fluorite specimens found there. Fluorite is a halide mineral that contains the elements Ca and F. These fluorite crystals are translucent with green centers and purple phantoms. They have characteristic stair step cuboctahedral habits. This piece measures 2 3/4 x 2 x 1 1/2 inches or 70 x 50 x 38 mm.