Stone is the generic term used to describe any rock or mineral also sometimes used to describe some hard, attractive objects such as pearls. Used for a variety of purposes from arrowheads, axes and knives in prehistory to casting moulds, cookware and houses and castles in the medieval era and beyond. Stones also were used as execution tools.
Stones can be divided into:
- gemstones- diamonds, emeralds, sapphires and rubies
- precious stones - stones of less value than the gemstones
- semi-precious stones -shiny, but usually not transparent eg opals, pearls
- other - rocks such as granite, slate, soapstone etc which are used in a variety of purposes, but usually not as jewellery.