Somewhat precious; as, semiprecious stones or metals. Used mostly of gemstones used in jewelry, such as amethyst, garnet, or iolite, which are sufficiently rare to have commercial value, but are not considered as precious, as are the diamond, emerald, and ruby.
Any gemstones valued for their beauty but which are not one of the four " precious stones", ( emerald, diamond, ruby or sapphire). Some examples of semiprecious stones are amethyst, aventurine, carnelian, garnet, opal, peridot, rose quartz, etc.