Quartz is a mineral compound formed of atoms of silicon and oxygen (SiO2).
Its chemical composition is 45.7% Si and 53.3% O.
Traces of Al, Na, Fe, Ca, Mn, Li, Cu, Cr and Ti are found, among others.
The physico-chemical properties which characterize the mineral are:
7.0 on the Mosh scale;
Melting point: 1775oC;
Density: 2.65g/cm3;
Refraction index: 1.54 to 1.55;
Soluble only in hydrofluoric acid at atmospheric pressure and temperature;
Low expansion coefficient;
Poor electrical conductor.
Si and O, elements which are widely present on the earth`s crust, lead to the formation of quartz deposits almost all over the planet. However only a few of these deposits are economically viable and have the necessary characteristics for technological applications. Among these, the Brazilian deposits stand out for the abundance of quartz with a high degree of purity.