QUARTZ IS THE SECOND MOST abundant mineral in the Earth’s continental crust. It is composed of silica, or silicon dioxide (SiO2) and can be found in most types of rock – igneous, metamorphic and sedimentary. Quartz is also reasonably hard, measuring seven on the Moh’s scale of hardness, and usually has a glassy lustre. Quartz is used in many different applications, ranging from pressure gauges, oscillators, heat-ray lamps, lenses and watch faces to being used in the manufacture of glass, paint and abrasive materials.
The quartz family is made up of many different varieties, with the major difference between the varieties being the make-up of crystals within the stone. Translucent or mostly opaque colours of quartz contain crystals that are only visible under high magnification (microcrystalline or cryptocrystalline) while transparent…