Apatite

Color: green, greenish yellow, blue, violet Hardness: 5 Refractive index: 1.60 - 1.67 Density: 3.17 - 3.35 Chemical composition: Phosphate composition Crystal structure: hexagonal Lustre: vitreous  Origins: Mexico, USA, Canada, Madagascar, Spain, Russia, Sri Lanka, India, Burma. Due to its insufficient hardness the stone is rarely used in jewelry production. However collectors do appreciate intensely colored blue and violet stones. Apatites are very heat sensitive. To invest in Apatite: wwwgemsinvestors.com