|
Chemical Composition: SiO2
Group: -
System: Hexagonal
Family: Silicates
Hardness: 7
|
- Well formed crystals, sometimes enormous, weighing up
to 130 kg (289 lb)
- Colourless when pure (rock crystal)
- The faces of the prism may be horizontally striated
- Often twinned
- No cleavage
- Good conchoidal fracture
- Nonmetallic; vitreous luster
- Light-transparent to translucent
- One of the commonest minerals of the earth's crust
(12% by volume)
- Amethyst quartz's violet colour is caused by trace
amounts of ferric iron
- specific gravity 2.65
- Found in: Canada, Czech Republic, Kazakhstan,
Slovakia, Sri Lanka, Uruguay, Zambia
|
