How many different quartz are there and what are they?
Quartz has many different habits, but only one crystal system category, trigonal, and one formula, SiO2. The various forms of quartz are a product of their method of formation or exposure to radiation or impurities. Some forms are agate, chalcedony, jasper, amethyst, chert, rose, citrine, smoky, milky, moss, flint, Cat’s Eye, Tiger Eye, prase, carnelian, rock crystal, and aventurine.
