buyers guide

What is Opal?

Opal, a stone in the Silica group, is a hardened silica gel and is composed of tiny layers of silica. When the layers are of similar size, light diffracts into the colours of the rainbow and so the opal looks like a flash of coloured light. – this is indicative of precious opal. Precious Opal comes in different colours including:

•    Black opal
•    Fire opal
•    White opal

These are the backgrounds for the iridescent colours which are typical of the opal. It is the most highly prized of the silica gemstones.

‘Common’ Opal is usually opaque.

It is found in the cavities of sedimentary rocks and in the veins of igneous rocks.

Opal is found in Australia, Brazil, USA and Mexico.