Fluorite Specimen

My personal favorite, this gem looks like something from another planet. Fluorite belongs to the cubic crystal system growing in near perfect cubes and has a frosted appearance. Its often regarded as the most colorful gem in the world coming in every color you can think of and sometimes even multiple colors in one stone

Fluorites can sometimes display phantoms where ghostly outlines of earlier crystal growths exist inside the stone and new layers grow over the existing ones, essentially a cube crystal within a cube crystal. If the inner one had a different mineral impurity you can get colors within colors, like a yellow cube with a blue cube in it, how wild is that?

Hardness: 4
Composition: CaF₂