
Gemstones
What Is Crystal? Quartz, Crystal Glass and the Names in Between
The word crystal covers a mineral, a man-made glass and a marketing category. A gemmologist's guide to telling them apart, what quartz actually is, which treatments you are entitled to be told about, and why two stones with the same name can differ in price by a factor of fifty.
Priya Raghavan · Updated October 22, 2026







