Opal is a hydrated amorphous form of silica; its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classed as a mineraloid, unlike crystalline forms of silica, which are classed as minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock. Opal is softer and more easily chipped than most other popular gemstones. It has a hardness of about 5.5 to 6.0 on the Mohs hardness scale.

Pink opal veins range in thickness from half a centimeter to maximum 6 cm, most commonly at around 1 to 2 cm of thickness. Pink opal ranges in color from nearly white, through carnation pink, through lilac, with the latter being the rarest and most expensive quality. High quality pink opal rough stone does sell for up to 2000 $US per kilo and is of course only used for jewelry. 

Pink Opal forms botryoidal layers. We are offering such specimens in flats.