Crystal Opals – A Rainbow Trapped in Stone – opalmine shop here
Crystal opals are transparent to translucent opals of very high purity and when opaque (non see-through) can also be known as milk opals or white opals. Like all opals they are a hydrated silica. Please go to the opal encyclopaedia on this site for a full technical description. They are completely solid and are the second most precious form of opal after Black opal.
The region of Coober Pedy in South Australia is a major site for mining crystal opal along with Andamooka and white cliffs. A certain amount of crystal opal is found in all fields. Like all opal, when white light falls on a crystal opal, it gets diffracted and is visible as several distinct colors of brilliant clarity inside the opal. The play of light from a crystal opal is breathtakingly beautiful and forces you to look at it. In fact it has been said that a good opal looks at you more than you looking at it.
Patterns in Crystal Opals
Crystal opal shows a variety of patterns and may show multiple patterns in a single specimen. Some of the observed patterns are:
- Broken Flash: shows a dominant flash of two different colors across the entire opal surface, with each color seen at a different angle
- Contra Luz: shows a play of color when held against white light
- Exploding Flash: shows a single prominent color that seems to burst radially outwards on moving the opal
- Eye-of-Opal: refers to an eye-like appearance seen when an opal enters into and fills a cavity
- Lechosos: refers to green hues in milk opals
- Gossamer Veil: a thin sheath of delicate hues is seen instead of definite regions of color
Preparing Crystal Opals for Jewelry
Crystal opals are commonly used in opal jewelry. The stone is first cleared of impurities by the opal cutter and fashioned into a round, oval, teardrop or free form shape with the help of diamond and carborundum machinery. Sandpaper is often used in the completing process along with a paste called ‘cerium oxide’ The dome of the stone is polished to enhance and perfect the play of color observed. Some of the more transparent crystal opals are also cut in a faceted manner like diamonds and other precious gems, although the most popular and practical shape is domed. Others are cut square and flat so that they can be inlaid into jewelry.
Crystal opal comes in a range of designs for brooches, necklaces, pendants, rings, earrings, tie-pins etc. Click here to learn more about these delicate beautiful stones Crystal opals