NON-FACETED AND FACETED GEMS
Gems that are heavily included or flawed, coloured or patterned, opaque or translucent are generally fashioned as beads and carvings or cut as a cabochon. A cabochon consists of a domed polished top with a flat, unpolished back and has an oval or round outline. It is the simplest and oldest style of cut. It is also used to show the optical effects of iridescence, sheen, cats'-eyes (or chatoyancy), and star stones (or asterism).
Most transparent gemstones are faceted. The gems are cut and polished such that they have a number of flat polished surfaces (facets). The number of facets and the angles between them are worked out mathematically, so that the facets act as mirrors that allow the maximum amount of light to enter the stone and also be reflected
back out of the front of the stone to the viewer. A well-cut gemstone will be cut to show the body colour, brilliance, fire, and sparkle to its best effect. However, a compromise usually has to be found to reach a good balance between these four attributes, which will give the final appearance - referred to as the 'make' of the stone. It may also be necessary to retain as much weight as possible, as the weight of the gem directly influences its value.
