Painite: Gemstone Information
Painite is CaZrBAl9O18 and occurs as elongated, pseudo-orthorhombic transparent deep garnet-red crystals of the hexagonal system with hardness near 8 and SG 4.01–4.03. The RI for the ordinary and extraordinary rays is 1.8159 and 1.7875 uniaxial negative with birefringence 0.029.Pleochroism is ruby-red and pale brownish orange or pale red-orange. So far painite has been found near Ohngaing, Myanmar and nowhere else.Less than 10 specimens are known so far to exist though some may be masquerading happily as garnet! Accounts of the discovery of painite can be found in the mineralogical literature, e.g. Claringbull, Hey and Payne, Mineralogical Magazine 31, 420–425, 1957. As I write a deposit of slender prismatic reddish pink brown crystals is being examined at GemA, London. They originate from Myanmar.