It is found in all forms of rock: igneous, metamorphic and sedimentary. Quartz is physically and chemically resistant to weathering. When quartz-bearing rocks become weathered and eroded, the grains of resistant quartz are concentrated in the soil, in rivers, and on beaches. The white sands typically found in river beds and on beaches are usually composed mainly of quartz, with some white or pink feldspar as well.
Pure quartz is clear. Color variance due to impurities: purple amethyst , white milky quartz , black smoky quartz , pink rose quartz and yellow or orange citrine. It is found is all forms of rock: igneous, metamorphic and sedimentary. Quartz crystal is found in many countries and many geologic environments. Major producers of natural quartz crystals are the United States particularly Arkansas and Brazil.
Natural quartz is rarely used as found in nature especially in electrical applications , except as a gemstone. Natural quartz crystals have too many chemical impurities and physical flaws. As a result, a commercial process of manufacturing pure, flawless, electronics-grade quartz was developed. Charles Sawyer invented the commercial quartz crystal manufacturing process in Cleveland, Ohio, United States.
This initiated the transition from mined and cut quartz for electrical appliances to manufactured quartz. Quartz's piezoelectric properties were discovered by Jacques and Pierre Curie in The quartz oscillator or resonator was first developed by Walter Guyton Cady in [2]. George Washington Pierce designed and patented quartz crystal oscillators in [3]. Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in [4].
Quartz crystals are rotary polar see rotary polarization and have the ability to rotate the plane of polarization of light passing through them. They are also highly piezoelectric, becoming polarized with a negative charge on one end and a positive charge on the other when subjected to pressure.
They will vibrate if an alternating electric current is applied to them. This proves them to be highly important in commerce for making pressure gauges, oscillators, resonators and watches. Quartz crystals have piezoelectric properties, that is they develop an electric potential upon the application of mechanical stress.
An early use of this property of quartz crystals was in phonograph pickups. One of the most common piezoelectric uses of quartz today is as a crystal oscillator. The quartz clock is perhaps the most familiar device using the mineral.
The same principle is also used for very accurate measurements of very small mass changes by means of the quartz crystal microbalance. Categories: Quartz varieties Dielectrics.
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Topics A-Z. All topics. To top. About chemeurope. Colorimetry-Software Day Free Trial. Your browser is not current. Microsoft Internet Explorer 6. Your browser does not support JavaScript. To use all the functions on Chemie. DE please activate JavaScript. Quartz Quartz Quartz crystal group from Arkansas.
Chemical formula. Silica silicon dioxide, SiO 2. Crystal habit. Crystal system. Mohs Scale hardness. Refractive index.
Melting point. Contents 1 Crystal habit 2 Varieties 2. Any cryptocrystalline quartz, although generally only used for white or lightly colored material. Otherwise more specific names are used. Tiger's eye. Fibrous gold to red-brown coloured quartz, exhibiting chatoyancy. Rose quartz.
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