Chalcantite CuSO₄ x 5H₂O Chalcantite is copper sulfate. Chemical formula CuSO4 x 5H2O Beautiful blue color. This color is the result of a copper mineral composition, and thus color can be considered as natural.
Alum chromium potassium, formula KCr (SO4)2 x 12H20 It crystallizes in a regular shape of the crystal as a cube. It crystallizes in the cubic forms of the ordinary. This piece was created in the laboratory in Poland.
PRUSKITE This mineral does not exist in nature. It was grown in lab in Poland. The red colour is natural and comes from iron. Thise chemical compound is used to develop film the classic way. In Europe it is additive to salt for the roads. It isn't toxic, however it is not edible - do not lick it, and do not eat.