A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments. Gems, or gemstones as they are sometimes called, are any material that can be cut and polished for use in jewelry, sculptures or other valuables. They can be formed from minerals, rocks, other inorganic materials or organic materials. Some can even be made synthetically.