Cabochon Stones
We're used to thinking of gemstones as being cut in a variety of styles so that the smooth faces reflect the light. An alternative approach is to shape the stone into a cabochon.
What Is A Cabochon?
A cabochon - also known as a cab - is a stone that has been formed into a smooth shape rather than one with numerous flat facets. The surface of the stone is usually highly polished to improve its appearance. Some cabochons are reflective, some near transparent and some opaque. The cabochon approach is often used to reveal an interesting aspect of appearance such as banding or a star effect.In theory any stone can be used as the basis for a cabochon. In practice some gems such as diamonds are rarely cut this way - you're more likely to find formally cut diamonds supporting a central cabachon of a different stone. The cabachon style is more normally used on stones which have an aesthetically pleasing internal pattern or which are too soft to carry a faceted cut. It also forms a good basis for a wire wrap with the stone often wrapped in silver wire.
Cabochons don't have to be made from precious or even semi-precious gems. Other materials such as coloured glass, porcelain and ceramics are sometimes formed into cab shapes.
Shapes
There's almost no limit to the number of different shapes in which you can buy cabochon stones, however certain styles are especially popular: these include ovals, hearts and tear drops. A cabochon stone can also form the centre of a multi-stone piece in a more complex design such as a flower.One feature shared by many cabochons is a flat rear surface. This allows for easy setting into a ring or brooch. Fully rounded stones are used in some items such as pendants, beads and earrings, however there is disagreement as to whether these should be called "cabochons".
Despite all these variations the convex oval is still the most frequently seen style of cabochon, perhaps because it makes maximum use of many original stones. It's also a more "forgiving" design than some of the others.