California is widely known for its tourmaline and turquoise production. Native Americans were the first to treasure these minerals, and a commercial gemstone industry was active by the late 1800s. The tourmaline deposits of Riverside and San Diego Counties have supplied more tourmaline for cutting and mineral specimens than any other tourmaline deposits in the northern hemisphere.

California gemstones also include many varieties of agate, jasper, jade, garnet, and quartz. The state is one of the only sources of benitoite, a blue barium titanium silicate, and it has been named the state gemstone. The image at right is a Vesuvianite cabochon cut from material produced at the Happy Camp mine in Siskiyou County.