Rock crystal was used in ancient times for many types of objects — tools, decorative pieces, drinking vessels, optical devices and jewelry. When used in necklaces, rock crystal was often paired with colored stones and was carved into various shapes including teardrop, barrel, and disk forms.
Polished rock crystal spheres, or crystal balls, were used as a means of divination since medieval times. Rock crystal was also used to create the first crystal chandeliers. A few hundred years ago, endless pieces of rock crystal were cut and polished by hand to create thousands of glittery chandeliers for France's Palace of Versailles.
Many crystals are believed to have healing powers. Rock crystal is said to stimulate mental clarity, help stabilize the emotions and alleviate stress. Rock crystal is also thought to help foster positive thoughts.
While rock crystal is found all over the world, most of the gem-quality variety comes from Brazil, Madagascar, China, and the United States.
Rock crystal quartz is fairly hard (7 on the Mohs scale), but you should protect your jewelry from sharp blows, scratches and extreme temperature changes. Clean your rock crystal rings, earrings, necklaces and rock crystal bracelets with warm soapy water and store them in a jewelry box when not in use.