#crypto! crypto crystalline

https://www.wirejewelry.com › cryptocrystalline-quartz

Because the cryptocrystalline quartzes can include several non-quartz minerals, many of these quartzes are considered "rocks," rather than macrocrystalline amethyst, citrine, tigereye, and smoky quartz, which are more likely called "gems" or "stones" due to their purity.