Semi-Precious Gemstone
se·mi pre·cious gem·stone | ˈse-mē-pre-shəs jem-ˌstōn
noun
A stone that is less rare and less expensive than precious stones, but is still valued for its beauty
While precious gemstones refer only to the four primary stones–diamonds, rubies, sapphire, and emerald–semi-precious gemstones can refer to a number of other types of naturally occurring stones. These are stones that are less rare and therefore less expensive than precious stones. They are, however, still frequently quite beautiful and somewhat rare compared to non-precious or synthetic materials. Modern semi-precious gemstones include beryl, chalcedony, agates, onyx, tourmaline, spinel, topaz, turquoise, zircon, amethyst, Alexandrite, cat's eyes, bloodstones, moonstones, and sunstones.