Chalcedony

Chalcedony occurs in a wide range of varieties that includes many semi-precious gems. Recognizable varieties include agate, carnelian, chrysoprase, fire agate, heliotrope, moss agate, chrome chalcedony, and onyx. With this range also comes a range of hues, although chalcedony is most often found in white to gray, grayish-blue or brown ranging from light to dark. The color sold commercially is often enhanced or changed by dyeing or heating the sample. It may be either semi-translucent or translucent and has a waxy luster, which is comical since chalcedony was used to make seal impressions as the wax would not stick to the gem. It was also used in other forms of tool making as early as 32,000 BP in Australia.