Quartz

Quartz. CAS: 14808-60-7. SiO2 HSN : 25061020

Crystallized silicon dioxide (silica).

Properties: Color white to reddish, luster vitreous,
Mohs hardness 7, d 2.65, insoluble in acids except hydrogen fluoride, only slightly attacked by solutions of caustic alkali, piezoelectric and pyroelec tric, mp 1713C. Noncombustible.

Derivation: Synthetic crystals of good size and purity are grown by mass production methods under very carefully regulated conditions of tem perature and concentration.

Hazard: Avoid inhalation of fine particles. TLV (for respirable dust) 10 mg/m³/% respirable quartz + 2.

Use: Electronic components, piezoelectric control in filters, oscillators, frequency standards, wave filters, radio and TV components; barrel-finishing abrasive.
See also silica