Quartz

Silica (SiO2) is one of the most wide-spread minerals. It is contained by most of rocks - both magmatic and metamorphic, and sedimentary rocks. Quartz is resistant to weathering (rock degradation), so the sand mainly consists of quartz grains, because other less resistant minerals have been degraded. The melting temperature of quartz is 1650 (±75) °C. In Latvia, quartz very often occurs as a part of the rock brought by the glacier. Quartz is used in very many spheres – in the manufacture of optics, precision machine construction, ceramics, electrical engineering, metallurgy, laboratory vessel production, construction material industry, jewellery production and elsewhere. Deposits of quartz sand suitable for industrial use (weakly cemented sandstone) occur relatively rarely in the subterranean depths of Latvia, and only the sand of the deposit "Bale - Berzini" has been specially explored and approved as a raw material for production of glass and dry construction materials, as well as for metallurgy. Research of the deposit "Bale - Berzini" was performed from 1959 to 1960; it was carried out by the Latvian Geology and Subterranean Depths Protection Office. This geological research has resulted in a number of separated deposit sites. According to the results of this research, averages of quartz sand chemical composition are as follows: SiO2  98,09%, Fe2O3 0,16%, TiO2 0,21%, but in the granulometric composition, the material of medium-grained and small-grained fraction (0.1-0.6 mm) prevails.