EPS2 Students: this material will not be covered in examinations
Quartz occurs in a wide range of
crystal sizes, from single crystals weighing many tons to
cryptocrystalline varieties whose crystallinity may be seen
only with the aid of an electron microscope.
quartz is believed to have originated in the early 1500s
from the Saxon word querklufterz (cross-vein ore), which
was corrupted to quererz and then to quartz. Quartz was
well known to the ancients, who called it crystal or rock
crystallizes in the trigonal trapezohedral class of the
rhombohedral subsystem of hexagonal symmetry.
Vigorous rubbing of one quartz
crystal by another may also produce visible light
Quartz is used as a component of glass, ceramics,
refractories, cements, and mortar; as an abrasive; as a
chemical raw material for the manufacture of sodium
silicate, silicon carbide, silicon metals, organic
silicates, and silicones; and as a component in numerous
other industrial materials.