Chalcedony is the general name for a variety of colored quartzes, many of which have a creamy appearance and luster. The gemstones given the name chalcedony are usually white to bright blue, while other colors have been given separate names--for instance, black onyx, green chrysoprase, and orange carnelian.

Gem quality druzy is created when a layer of tiny quartz crystals forms over the top of another stone. Natural druzy crystals can be colored themselves or take their color from the underlying stone. The surface of a druzy is sometimes coated with gold or other substances for a dramatic effect. Titanium druzy has been treated with a thin layer of titanium to give it a beautiful color and iridescent sheen.