Quartz

Quartz is amongst one of the most common and precious minerals in the Earth's continental crust. It has a hexagonal crystal structure made of the trigonal crystallized silica (silicon dioxide, SiO2), with a hardness of 8 on the Mohs scale. Density is 2.66. The typical shape is a six-sided prism, which ends in six-sided pyramids, although these are often twinned, distorted, and so massive that only part of the shape is apparent from a mined specimen. Additionally it has bed is a common form, particularly for varieties such as amethyst, where the crystals actually 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 the crystals.

History

The name "quartz" has comes from the German "Quartz", which is of Slavic origin (Czech miners called it ken). Other sources insist the name is actually from the Saxon word "Quarks luster", meaning cross-vein ore.

Quartz is the one of the most common material identified as the mystical substance Maben in Australian Aboriginal mythology.

Roman naturalist Pliny the Elder had believed quartz to be permanently frozen ice. He supported this idea by saying that quartz is found easily near glaciers in the Alps and that large quartz crystals were fashioned into the spheres to cool the hands. He also knew of the ability of quartz to split its light into a spectrum.

Nicolas Steno's study of quartz paved the way for modern crystallography. He discovered that no matter how it was distorted a quartz crystal, the long prism faces always made a perfect 60 degree angle.

Charles Sawyer invented the commercial quartz crystal manufacturing process in Cleveland, OH. This was initiated the transition from mined and then cut quartz for electrical appliances to manufactured quartz.