Quartz (SiO2) is, next to feldspar, the commonest mineral. It is an important rock-forming mineral, being one of the main components of the majority of granites and other igneous rocks. Under conditions favorable for crystallization, such as voids in rock, it forms sharp-pointed hexagonal long and slender crystals which are widely used as a popular ornamental stone and also a gemstone in jewellery. Depending on admixture of coloring oxides, several varieties of these gemstones are differentiated: clear and colorless rock crystal, yellow to orange citrine, pink to rose red rose and pink quartz, purple to violet amethyst, brown to gray smoky quartz and black morion.
Quartz also forms veins and lenses in metamorphic and igneous rocks. Quartz vein deposits originate in result of hydrothermal activity as an infill of open fissures and fractures cutting a given rock massif. The quartz infills are characterized by high content of silica (SiO2) and low content of coloring oxides (Fe2O3 and TiO2).
In Poland quartz veins occur mainly in crystalline rock massifs of the Precambrian and Paleozoic in the Sudety Mts (map). The deposits are characterized by a high variability in thickness and quality of raw material as well as in generally high dip of veins and lenses. Prognostic resources of vein quartz are assessed to be equal 2.87 million tonnes and prospective resources 1.33 million tonnes(1).
Vein quartz is widely used in the industry, starting from ceramic industry (production and glazing and decorating bone and fine china, porcelain and porcelite, utility and pottery ware ceramics, technical ceramics) to production of fire-proof materials and in metallurgy. Its purest varieties are used in manufacturing high-quality glass and in chemical and electrotechnical industries. Quartz vein is also the source of high-quality quartz powder and fine grade crushed grains.
The table 1 given below shows resources and the current state of exploration and development of deposits of vein quartz.
Anticipated economic resources of vein quartz within 7 documented deposits has not changed since 2010 and amounted to 6.56 million tonnes in 2012.
There are three exploited deposits – Krasków, Stanisław and Taczalin. Economic resources of these deposits are equal 3.23 million tonnes which accounts for 50 % of their anticipated economic resources. None of them is being currently exploited – production from Krasków deposit was suspended in 2007 whereas from Stanisław and Taczalin deposits in 2005.
Prepared by: Agnieszka Malon
(1)K. Wołkowicz, C. Sroga, 2011 - "Kwarc żyłowy" in "Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31 XII 2009 r." editors: S. Wołkowicza, T. Smakowskiego, S. Speczika. PIG-PIB Warsaw.