Collection of 4 minerals on base. pyrite, malachite, calcite, chalcopyrite

A mini collection of minerals, but very varied and powerful colors. Obviously we have not chosen these minerals at random, but indeed for their great variety: The optical calcite of Mexico is transparent, but this Optical Calcite has a strange ability: the double refraction. Everything you look through this mineral (like a book) is split. The light beam that passes through it is divided in two. Malachite from Congo is incredibly green, the result of the oxidation of copper over millennia. Peru’s pyrite, or fool’s gold, shines with golden lights. And Mexico’s chalcopyrite. It is a mineral of hydrothermal origin that is part of the copper sulphides and has beautiful colors.