Crystal cut to be used in jewelry is most often-manmade; otherwise, it is named for the kind of gemstone crystal it comes from. Manmade cut glass crystal is created using a combination of silica (quartz sand) and natural minerals. It is naturally colorless, but is also available in myriad colors and with different coatings to affect appearance. To avoid stress and inclusions, the glass is cooled slowly.
Crystal has a Mohs hardness rating of 7, making it a good choice for all styles of jewelry.