Quartz, the master healer. Pure quartz traditionally called rock crystal (or clear quartz) is colourless and transparent (clear) or translucent. Quartz goes by an array of different names. The most important distinction between types of quartz is that of macrocrystalline (individual crystals visible to the unaided eye) and the microcrystalline or cryptocrystalline varieties (aggregates of crystals visible only under high magnification).