Chalcedony is a gemstone species which belongs to the quartz group of minerals.Chalcedony occurs translucent to opaque, with translucent materials being more desirable. It has an attractive luster when cut and polished, often appearing waxy or vitreous to dull. Generally, chalcedony is often milky with obscured color. The cloudy distribution is a good indication of authenticity and as long as translucency is not affected, the milky clarity does not significantly affect the overall value. Chalcedony often has visible inclusions which in most cases are considered acceptable.Chalcedony can technically refer to any translucent, cryptocrystalline quartz with a single color, but in the gem trade, it is primarily used to refer to specimens with light bluish, white or gray color. The most common colors for 'chalcedony in the narrow sense' include blue-white, buff, light tan, gray, yellow, or brown.