Fluorapatite is more commonly known as Apatite.. Apatite has a Moh's Scale hardness of 5

Gemology Apatite is now frequently used as a gemstone. Transparent stones of clean color are usually faceted, and chatoyant specimens are cut into cabochons. Chatoyant stones are known as cat's-eyes. Transparent green stones are known as the asparagus stone. Green and blue stones are the most valuable. Rutile may have grown in the crystal of apatite so when in the right light, the cut stone displays a cat's eye effect.

Crystal Specifications • Crystal system: hexagonal; 6/m • Crystal habit: prismatic crystals terminated by first order pyramids often with basal planes are common. Also can be in compact masses to massive granular. • Twinning: twins are rare but are readily found in the Afghanistan deposit • Specific gravity: 3.15 - 3.20 • Index of refraction: 1.63 - 1.64 • Birefringence: weak to moderate (0.001-0.015) • Pleochroism: weak to moderate • The color in apatite is often due to the presence of rare earth elements or by natural irradiation. • Apatite is characterized by its hardness, crystal habit and color. Much of the apatite on the market today is irradiated to bring out deeper colors and heated to improve clarity. All apatite we provide is all natural without any treatments