Home » The Gemstones » Opal


What is Opal?

Opal derives if names from the Sanskrit ‘Upala' meaning 'precious stone'. Opal is the birthstone for October and is in fact not a crystal but is formed as a microscopic array of minute spheres of silica of very uniform size which can reflect and break up light to give its characteristic play-of-colour.

There are a number of precious opal varieties that are named for their body colour, such as white, or black opal, or the fact that it is still in its host rock-type (and cut with it) like 'boulder' or 'matrix' opal. Fire-opal is a transparent to translucent brownish to yellow opal with little (if any) play-of-colour.

The values of precious opal are usually based around the opal type, what the background colour is and the intensity and brightness of the play-of-colour. It is often deemed that red is the rarest of the iridescent colours, but those that are strong and vivid in colour against a darker background are judged more valuable.

Home » The Gemstones » Opal