Chalcedony is a type of cryptocrystalline quartz, which is composed of very fine intergrowths of quartz and moganite. The term chalcedony is used to describe a variety of stones, including sard (4 letters), ONYX (4 letters), AGATE (5 letters), CARNELIAN (9 letters), JASPER (6 letters), AGATES (6 letters), and BLOODSTONE (10 letters). These stones are usually found in a variety of colors, ranging from white to gray to brown to reddish-brown. They are often used in jewelry and other decorative items.