Opals differ from each in colour, transparency. The Precious Opal has a unique colour effect. the basic colour is usually white, but it can also be blue, green, yellow, red, brown or even black. Different colour patches mark out from the basic colour, so called blazes, in the shades of red, yellow, blue, violet or green. These marks have sharp edges, or they are firmly melting into each other. The colour richness was explained mostly with the light iridescence in the small cracks.

A disadvantage of the Opal is that it is not hard enough. If it looses its colour because of drying out, people usually put the stone into a potato.

The value of the Opal highly depends on its quality: the more colourful it is, the more value it has, that rises together with the size of the stone.

The most beautiful Opals were found in Hungary, the most beautiful Precious Opals were found here. Unfortunately, our mines are mostly ran down.  It was mined several hundred years back. The Hungarian Precious Opal was transparent with red, green and violet-scented bright colours.

Most of the Opals are mined nowadays in Australia, in New-South Wales Queensland and South-Australia.

 Mohs:7.