Magical Natural labradorite silver 925 mark ring szs 4-12 cabochon stone size 6 x 8 mm gift box included A semi-precious stone is also known as a gem or gemstone (also a jewel, a gem, a precious stone), which is a portion of mineral, which, in refined and cut form, is used to create jewelry or other embellishments. There are also organic resources or precise rocks that are not minerals (for example jet or amber) that are also used for jewelry and would also be considered to be gemstones, as well. All semi-precious stones are different and have variations of colors and natural inclusions.