Stevens Koziol Field Geology Due 9-18-2014 Mineral Name Quartz Images (if mineral has a number a Amethyst variances, multiple pictures are necessary) Citrine Also known as: Agate (a banded form of the mineral chalcedony) Chemical formula Chalcedony, Amethyst, Citrine, and Agate but to name a few. There are more variety names given to quartz than any other mineral. SiO2 Mineral family/class Silicates; Tectosilicates; Silica Group Crystal system Hexagonal Cleavage Indiscernible Fracture Concoidal Color(s) Colorless, white, purple, pink, brown, and black. Also gray, green, orange, yellow, blue, and red. Sometimes multicolored or banded. Hardness (#) 7 Specific gravity Luster 2.6 – 2.7 Vitreous. Transparent, colorless Streak (color) White Locality/occurrence/ Countries it’s found in Quartz occurs in almost every single mineral environment. It is associated with all three rock types: Igneous, Sedimentary, Metamorphic Defining characteristics Hardness and crystal forms History – human discovery and uses One of the most well known minerals on Earth, occurs in basically all mineral environments and is an important constituent of many rocks. The use of quartz by humans can be traced back to prehistoric times, there are evidences of its use in making tools, religious objects in many countries and most continents. The hardness of quartz makes it particularly useful as an abrasive. It is a primary component in glass making. Its resistance to heat and chemical makes it useful as foundry sand. Its resistance to being crushed makes it useful in hydraulic fracking as a component of the mixtures pumps into well. The colorful and polished varieties are used as gemstones. World Reserves Very high purity quartz for advanced high-tech applications is currently sourced from just a few locations around the world. Sources J. Götze and R. Möckel (eds.), Quartz: Deposits, Mineralogy and Analytics, Springer Geology, DOI: 10.1007/978-3642-22161-3_2, Springer-Verlag Berlin Heidelberg 2012 "Quartz - A Ubiquitous Mineral with an Enormous Number of Uses." Mineral. Geology.com. Web. 12 Sept. 2014. < http://geology.com/minerals/quartz.shtml> Quartz Various Images. N.d. The Mineral & Gemstone Kingdom - The Mineral Quartz. Minerals.net. Web. 12 Sept. 2014. <http://www.minerals.net/mineral/quartz.aspx>.