Precious in the context of jewelry means “of high value” and is applied to both metals (platinum, gold, and silver) as well as to rare minerals that are used in jewelry. The term “precious stone” is equivalent to “gemstone” and is usually used to refer to Diamond, Ruby, Sapphire, and Emerald. Semi-Precious is an archaic (and strongly discouraged) term and it indicates minerals that are worn as gemstones but are more common and less expensive than gemstones such as diamond, corundum, or emerald.