Precious Gemstone
pre·cious gem·stone | ˈpre-shəs jem-ˌstōn
noun
A gemstone that is of a very high value or price, due to its rarity
A precious gemstone is a naturally occurring stone with aesthetically pleasing characteristics and a certain level of rarity that make it highly sought after. The result is a stone with a high cost, high demand, and exceptional rarity. Modern precious gemstones include diamonds, rubies, sapphires, and emeralds. There are other forms of stone and organic materials that have been considered precious as well, including opal and lapis lazuli, and pearls and amber. There are some precious gemstones that are now possible to craft synthetically or culture, however, naturally formed precious gemstones with minimal inclusions are still considered the mostly desirable.