Apatite is not a single mineral, but rather is a group of similar minerals that are more or less indistinguishable and are thus grouped together. Whilst the mineral apatite is common, gem quality Apatite is considerably rarer. This gemstone/mineral group is virtually unknown among the general public, but is well liked by gemstone collectors and industry insiders who appreciate the wide variety of colors it can be found in.
Etymology & Sources
Apatite can be difficult to distinguish from a variety of other more well known (and valuable) gemstones, and it is suspected that it is for this reason that it got the name ‘Apatite’, which is Greek for ‘cheat’ or ‘deceit’. Deposits can be found in many places around the world, including but not limited to Myanmar, Kenya, Brazil, Sri Lanka, India, Canada, and the US.
Apatite can be found in many colors; pink, green, blue, purple, yellow, and colorless/clear. Some colors are rarer and more sought after – vivid purple for example is quite rare and is seen as very desirable by collectors. Different colors of Apatite are often associated with different trade names – for example, lighter green apatite also goes by ‘asparagus stone’. The gemstone has a vitreous luster, and the material can range from transparent to translucent. Apatite can also exhibit Chatoyancy. This form of the mineral is known as Cat’s Eye Apatite, and it is exceedingly rare and quite valuable.
Apatite has moderate hardness, with a Mohs scale value of 5. It has specific gravity of about 3.2, and a refractive index of roughly 1.63-1.65.
Apatite is not particularly hard and jewelry applications that experience more wear and tear like rings and bracelets should be avoided. As with other low or moderate hardness gemstones, it is more suitable for use in pendants and earrings, and other forms of jewelry that will experience less contact with other potentially damaging materials. Transparent apatite is often faceted into the traditional gemstone shapes, but the rare Cat’s Eye Apatite is typically cut into cabochons to show off its Chatoyancy. Apatite also has non gemstone applications – the mineral is the primary source of the phosphorus used in fertilizers, and has vital applications in both the pharmaceutical and chemical industries.
Asparagus Stone – Light green variety of Apatite
Neon-blue Apatite – Sourced from Madagascar, Neon-blue specimens are quite popular with gemstone enthusiasts.
Violet Apatite – Violet Apatite with deep and saturated colors is quite sought after by collectors and comes from Maine.
Cat’s Eye Apatite – Rare form of Apatite that displays Chatoyancy; commonly cut into cabochons rather than faceted in order to fully display its Chatoyant effect.
Apatite is typically untreated, but occasionally it will be heat treated. The Blue variety in particular is often heat treated for enhanced color.