Quartz

: For other uses of this word, see Quartz (disambiguation).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Quartz is the most abundant mineral in the Earth's continental crust. It has a hexagonal crystal structure made of trigonal crystallized silica (silicon dioxide, SiO2), with a hardness of 7 on the Mohs scale. Density is 2.6 g/cm³. The typical shape is a six-sided prism that ends in six-sided pyramids, although these are often twinned, distorted, or so massive that only part of the shape is apparent from a mined specimen. Additionally a bed is a common form, particularly for varieties such as amethyst, where the crystals grow up from a matrix and thus only one termination pyramid is present. A quartz geode consists of a hollow rock (usually with an approximately spherical shape) with a core lined with a bed of crystals.

Related Topics:
Mineral - Earth - Continental crust - Hexagonal - Crystal - Trigonal - Silica - Mohs scale - Density - Typical shape - Prism - Pyramid - Twinned - Amethyst - Geode

~ ~ ~ ~ ~ ~ ~ ~ ~ ~