Quartz — the mineral which is most spread on the earth representing silicon dioxide capable to exist in different crystal modifications. The mass fraction of quartz in earth crust in pure form makes the whole 12%. The correct chemical name of this mineral — silicon dioxide, and its formula looks as SiO2.
In the nature quartz meets generally in sedimentary rocks — limestones or dolomite. In pure form SiO2 is called rhinestone and represents absolutely transparent colourless mineral.
Whether has a smell
As the smelling substances are not a part of quartz, this mineral has no smell absolutely. And it concerns not only rhinestone, but also the painted types of dioxide of silicon containing various impurity — amethyst, smoky quartz, a morion, a prazem.
To smell, and it is pretty sharp and unpleasant, only one type of SiO2 — vein quartz can. In geology such smell is even considered search sign for the non-ferrous and rare metals accompanying silicon dioxide.
However vein quartz begins to exude a smell only when splitting. That is its emergence, most likely, just is connected with availability of any impurity in structure of mineral as, for example, at the same smelly spar.
Sometimes people mistakenly take for a smell of quartz and a smell of ozone. It is explained by the fact that flasks of the medical lamps intended for destruction in air in rooms of pathogenic bacteria make of such mineral.
During the work of quartz lamps the light specific smell is really felt. However at all not dioxide of silicon, namely the ozone which is formed in the room under the influence of UV rays smells in this case.
Properties and application
Besides lack of a smell, it is possible to refer very high rate of density to features of dioxide of silicon — 2.6-2.65 g/cm3. Quartz concedes in this plan only to diamonds and corundum.
Also quartz differs in chemical stability. This mineral, for example, only in fluoric acid is dissolved. Also silicon dioxide melting temperature is very high. It is equal in usual conditions to 1570 °C.
Crystals of this mineral represent hexagons in which there is a set of the cracks and emptiness filled with other breeds. Druzes of quartz often reach the huge sizes and can weigh to several tons.
Quartz not only in lighting engineering, but also in electronics or cosmetology is used. This mineral found very broad application also in jewelry. Do not too expensive jewelry, souvenirs and also decor elements for interiors of quartz.