Stone or rock, is a naturally occurring solid aggregate of one or more minerals or mineraloids. They have been used by mankind throughout history. From the Stone Age, stones have been used for tools. The minerals and metals found in stones have been essential to human civilization.
Natural stones (stones that can be used in jewelry after cutting and polishing) are well-known for their vibrant colors, but are not one of the four precious stones (diamond, emerald, ruby, sapphire).