Apatite is infrequently used as a gemstone. Apatite value depends mostly on color saturation. Specimens with high color intensity are considered most valuable. Gem-quality apatite is rarely found in large sizes; stones over one carat can command very high premiums.Connoisseurs often seek out rare colors such as Paraiba-like blue-green apatite or leek-green apatite. When cut and polished, apatite has a vitreous luster. Gem-quality apatite typically occurs transparent, but translucent specimens do exist.
Source: Wikipedia
