Apatite is a stunningly beautiful stone that comes in a number of colours. It comes in various shades of blue, green, violet, pink, yellow, purple, and colourless. There's even supposed to be cat's eye variety. However, probably the most well known and desirable colours for Apatite are the blue and green varieties. As a mineral, it is relatively common, but is rare in gem quality. According to the 2005 printing of the "Gemstone Buying Guide," Apatite retails for between $25-$400 per carat for the blue or green transparent stones depending on stone quality. It is a hardness 5 and tends to lose or change colour when exposed to heat.
"About Apatite." GemSelect.com. 15 January 2008.