First of all, we can often see obsidian or chrysolite in crystal shops. But because of people's misunderstanding, Obsidian has always carried the identity of crystal. In fact, although the chemical composition of obsidian is similar to that of crystal, it belongs to volcanic glass, not crystal in the strict sense.

Secondly, at present, many unprofessional merchants in the market put some low-grade tourmalines and crystals together to sell, telling customers that tourmaline is a kind of crystal. Many people think that tourmaline is a kind of crystal with low price. Actually, this is not right. Tourmaline and crystal are two different minerals. Tourmaline is a high-grade gem in the jewelry industry, and high-quality tourmaline is even rarer than diamonds. Crystal is an ordinary gem.