Few specimens like these we offer were collected in this Peruvian mine, most of them were colorless, or only slightly bluish. On the contrary, some specimens appeared with a very remarkable sky blue color, and in this sample with a blue greenish tone, very unusual. They are tabular anhydrite crystals that have been almost totally pseudomorphized by chalcedony, as we can see in this specimen. We can observe inside the structures some zoning, even in botryoidal ones, with a lighter center and zoning bands of different shades of sky blue. In the outer part there is a thin layer of what could be identified as opal. Its behavior under UV light and sunlight stands out. An unusual and really aesthetic pieces. The main crystal is: 6,8 x 4,2 x 3 cm. 2,68 x 1,66 x 1,18 In.