A few gemstones are used as gems in the crystal or other form in which they are found. However most gems are cut and polished for usage as gemstones. Two of the most important classifications are:
1) Smooth cut or dome shaped stones called cabochons, and
2) Stones which are cut with a faceting machine by polishing small flat windows called facets at regular intervals at exact angles.
Opaque stones such as opal, turquoise, etc. are commonly cut as cabochons. These gems are designed to show the stone's color or surface properties as in opal.
Transparent stones are normally faceted, a method which shows the optical properties of the stone�s interior to its best advantage by maximizing reflected light which is perceived by the viewer as sparkle. There are many commonly used shapes for faceted stones.
Last edited by benifer; 09/05/08 07:04 AM.
