There are very few gemstones which are predominantly gray or silver. When most people think of silvery gray gemstones, the silvery adularescence of moonstone is usually one of the first to come to mind, but there are actually a number of other gemstones available in various shades of gray, silver or charcoal-like color. The most popular gray gemstone is spinel, though with spinel, grayish color is more of secondary hue as seen in many fine examples of grayish blue
spinel gems. Spinel has remarkable brilliance and its single refraction properties allow it to show gray and silver color at its best. Other fine examples of silver gems include precious pearl and metallic gems such as
hematite and pyrite. Most gray gemstones are normally
multicolored gems rather than being pure gray, with shades of black, brown and beige being quite common. Transparent gray gemstones like spinel are typically faceted, while opaque silver/gray gemstones are almost always cut en cabochon, though faceted opaque gems are still readily available but just harder to source.