Gem Minerals
Fluorite
What it is
Calcium fluoride that forms perfect cubes and octahedra, often with stunning internal color zoning. Fluorite comes in every color and frequently fluoresces under UV light — in fact, the word "fluorescence" was coined from this mineral. Despite its beauty, fluorite is too soft (Mohs 4) for most jewelry.
How it forms
Crystallizes from hot hydrothermal fluids in limestone veins and around granite intrusions. The color zoning reflects changing fluid chemistry during growth.
CaF₂ (Isometric/Cubic)
