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Quartz biography, Quartz discography
Uses: silica for glass, electrical components, optical lenses, abrasives,
gemstones, ornamental
stone, building stone, etc.The Physical Properties of Quartz.Quartz is the most common mineral on the face of the Earth.It is also
the most varied in terms of varieties, colors and forms.This variety comes
about because of the abundance and widespread distribution of quartz.Amethyst
is the purple gemstone variety.Milky Quartz
is the cloudy white variety.Rock crystal
is the clear variety that is also used as a gemstone.Rose quartz
is a pink to reddish pink variety.Smoky quartz
is the brown to gray variety.Quartz is not the only mineral composed of SiO2.There are no less than eight other known structures that are composed of
SiO2.Quartz
Group or Silica Group.All members of this group, except quartz,
are uncommon to extemely rare on the surface of the earth and are stable
only under high temperatures and high pressures or both.These minerals
have their own unique structures although they share the same chemistry,
hence the term polymorph, which means many forms.Quartz has a unique structure.Actually, there is another mineral that
shares quartz's structure, and it is not even a silicate.It is a rare phosphate
named berlinite,
AlPO4, that is isostructural with quartz.The structure
of quartz involves corkscrewing (helix) chains of silicon tetrahedrons.The corkscrew takes four tetrahedrons in order to repeat itself, or three
turns.The chains
are aligned along the C axis of the crystal and interconnected to
two other chains at each tetrahedron making quartz a true tectosilicate.The structure of quartz helps explain many of its physical attributes.For one, the helix makes three turns and this helps produce the trigonal
symmetry of quartz.Likewise a helix or corkscrew lacks mirror planes of
symmetry as does quartz.Quartz can also have left and right handed crystals just as a corkscrew
can screw in a left handed way or in a right handed way.There are even
some very difficult to identify crystals of quartz that are twinned with
alternating one sixths of the crystal being right handed and then left
handed.Quartz is a fun mineral to collect.But nearly all collectors
concede that you can never really have enough quartz specimens.Color is as variable as the spectrum, but clear quartz is by
far the most common color followed by white or cloudy (milky quartz).Purple
(Amethyst), pink (Rose Quartz), gray or brown to black (Smoky Quartz) are
also common.Cryptocrystalline varieties can be multicolored.Transparency: Crystals are transparent to translucent, cryptocrystalline
forms can be translucent or opaque.Hardness is 7, less in cryptocrystalline forms.Other Characteristics: Striations on prism faces run perpendicular
to C axis, piezoelectric (see tourmaline)
and index of refraction is 1.Rose Quartz is also wide spread but large quantities come from brazil as
do the only large find of Rose Quartz prisms.Fine examples
of Rock crystal come from Brazil (again), Arkansas, many localities in
Africa, etc.Best Field Indicators are first the fact that it is very common
(always assume transparent clear crystals may be quartz), crystal habit,
hardness, striations, good conchoidal fracture and lack of good cleavage.By Class
Elements, Oxides, Carbonates, etc.If you gaze deep into a crystal ball, you will see a versatile gemstone, one of the most popular gems on earth.Beautiful quartz, the 'rock crystal' used in ancient times to make crystal balls and bowls, is today more often seen set in gold jewellery.Despite the popularity of quartz gems like amethyst, citrine,
ametrine, rose quartz, onyx, agates, chrysoprase, rutilated quartz and other varieties, many people in the jewellery industry take quartz for granted because of its affordable price.Throughout history, quartz has been the common chameleon of gemstones, standing in for more expensive gemstones ranging from diamond to jade.But the incredible variety of quartz is now beginning to be appreciated in its own right.Purple to violet amethyst and yellow to orange citrine are jewellery staples that continue to increase in popularity.Different colours and types of chalcedony, from agate to chrysoprase, have grown in popularity with the growing appreciation for carved gemstones and artistic cutting and carving.The pale pink colour of quartz, which can range from transparent to translucent, is known as rose quartz.Transparent rose quartz is very rare, and usually so pale that it does not show very much colour at all except in large sizes.Translucent rose quartz is much more readily available, being used for beads, cabochons, carvings, and architectural purposes.Smoky quartz is a brown transparent quartz that is sometimes used for unusual faceted cuts.Tiger's eye quartz contains brown iron which produces its golden yellow colour.Cabochon cut stones of this variety show the chatoyancy (small ray of light on the surface) that resembles the feline eye of a tiger.The transparent, colourless variety of quartz is still known as rock crystal.Long ago, people believed that rock crystal was a compact form of ice: in fact 'crystallos' means 'ice'.The best rock crystal has the clarity and shimmer of water.Although colourless quartz is relatively common, large flawless specimens are not, which is why crystal balls these days are made of glass, not quartz.Rock crystal has often been used in jewellery, particularly carved pieces.Many stunning art deco jewellery designs featured the black and white quartz combination of rock crystal and onyx.Colourless quartz crystals have also become popular in jewellery due to the popularity of legends about their powers.While most varieties of transparent quartz are valued most when they show no inclusions, some are valued chiefly because of them!The most popular of these is known as rutilated quartz.Rutilated quartz is transparent rock crystal with golden needles of rutile arrayed in patterns inside it.Each pattern is different and some are breathtakingly beautiful.Less well known is a variety called tourmalinated quartz which, instead of golden rutile, has black or dark green tourmaline crystals.Quartz that is formed not of one single crystal but a number of finely grained microcrystals is known as chalcedony.The variety of chalcedonies is even greater than that of transparent quartz, including cryptocrystalline quartz with patterns as well as a wide range of solid colours.Bloodstone has red spots on a green background.Jasper sometimes looks like a landscape painting.Another staple of the jewellery industry is black onyx, chalcedony quartz which owes its even black colour to an ancient dyeing process that is still used today.It was a particular favourite of Frederick The Great of Prussia.It can be seen today decorating many buildings in beautiful Prague, including the Chapel of St Wenceslas.Unlike most other green stones, which owe their colour to chromium or vanadium, chrysoprase derives its colour from nickel.How many different ways can SiO2 be organized into a neutral structure?That is what the Quartz Group is all about.An alternate name for the Quartz Group is the Silica Group.Silicon and oxygen are the two most common elements in the Earth's crust, so perhaps their diverse modes of organization are not so unexpected.But in reality it is simply a matter of the temperature and pressure, especially at the time of crystallization, that determines which form silicon dioxide will organize into.The classification of the Quartz Group has been up for debate and the ultimate ruling is still undecided.Quartz and most of the other Quartz Group members are classified here as silicates because of their structural and property similarities to other tectosilicates.Quartz Group because they also contain SiO2 are classified as mineraloids.An interesting comparison within the quartz group is between the high temperature minerals, high pressure minerals and quartz.Both high temperature minerals, cristobalite and tridymite, have both a lower density and index of refraction than quartz.The high pressure minerals, stishovite and coesite, on the other hand, have a higher density and index of refraction when compared to quartz.This is probably due to the intense squeezing together of the atoms that must occur during their formation and the condensed structure that they are actually forced into forming.At surface temperatures and pressures, quartz is the most stable form of silicon dioxide, to no ones surprise.Quartz will remain stable up to 573 degrees Celsius at 1 kilobar of pressure.As the pressure increases the temperature at which quartz will lose stability also increases.Above 1300 degrees and at a pressure of approximately 35 kilobars, only beta quartz also known as high quartz is stable.Beta quartz is not the same as normal quartz, actually referred to as alpha quartz, low quartz or, as is mostly done here, just quartz.Beta quartz has higher symmetry, is less dense and has a slightly lower specific gravity.The conversion, from one solid substance to another solid substance, of quartz to beta quartz is quick, reversible and accompanied with a slight energy absorption.The reason that the conversion is so easily accomplished is that the difference between quartz and beta quartz is relatively slight.The bonds between the oxygens and silicons are "kinked" or bent in quartz and are not so "kinked" in beta quartz.Although all quartz at temperatures lower than 573 degrees Celsius is low quartz, there are a few examples of crystals that obviously started out as beta quartz.Sometimes these are labeled as beta quartz but are actually examples of pseudomorphic or "falsely shaped" crystals more correctly labeled 'quartz after beta quartz'.These crystals are of higher symmetry than low quartz although low quartz can form similar crystals to them.Quartz's typical termination is composed of two sets of three rhombic faces that can look like a six sided pyramid.Other differences between beta quartz and quartz are shown in the table below.Keatite is a synthetic substance that has only been produced in a laboratory.Some of keatite's physical characteristics are listed in the table below.Just like quartz and beta quartz, there exists phase relationships with cristobalite and tridymite and higher symmetry phases referred to as betas.They both are higher temperature phases than the lower temperature minerals.They both have higher symmetries and lower densities than their mineral "brothers".Interestingly the structure of beta cristobalite is analogous to the structure of diamond.These bonds lay as far apart from each other as four bonds can get in three dimensions or in a tetrahedral shape.By replacing the tetrahedrons in the diamond structure with the tetrahedrons of SiO4, we get approximately the structure of beta cristobalite.The sheets are unlike the sheets of the phyllosilicates in that these sheets are linked together by strong oxygen to silicon bonds.The tetrahedrons alternately point up then down to connect to the sheets above and below making tridymite's true tectosilicate structure.H2O) and a very rare pure silica glass called lechatelierite, SiO2 are amorphous, do not have symmetry and have variable properties, but they are sometimes considered to be a part of the Quartz Group.Tridymite's symmetry was considered to be orthorhombic; 2 2 2 , but it is probably monoclinic.By Class
Elements, Oxides, Carbonates, etc.Occurs in an infinite range of colors.The crystals are commonly large, single, and faultless.Quartz crystals from a few distinct localities
have an adamantine luster.Quartz or High Quartz
(describes Quartz stable at normal room conditions.There are literally hundreds of different
names given to Quartz and Chalcedony.The information provided here just briefly
touches upon all the details of this mineral.Quartz is also the most varied of all
minerals.There are more variety names given to Quartz than
any other mineral.The mineral Chalcedony, is, in essence, a variety of
Quartz.Quartz that only occurs in
microscopic, compacted crystals.Quartz and Chalcedony as two separate
minerals.This page deals only with crystalline (form in
visible crystals) Quartz.There are light blue, transparent Quartz crystals in the
market.Crystal (transparent colorless Quartz crystals)
synthetically tinted with irradiation of gold.In some localities, Hematite forms an incrustation pseudomorph over Quartz crystals.Quartz frequently forms the inner lining of geodes.The geodes may contain large crystals, or
may be of globular, microcrystalline Quartz.Quartz is an important mineral with numerous
uses.Sand, which is composed of tiny Quartz pebbles, is
the primary ingredient for the manufacture of glass.Quartz is also used as an abrasive for sandblasting, grinding glass, and
cutting soft stones.Quartz is important in the production of soaps and
ceramics.Transparent Rock Crystal is used in
the study of optics.Beside for all these practical uses, Quartz is important
in the gem trade.Quartz gem, and Citrine is the most
valuable.Crystal, and Aventurine are also cut into
gems.Clear Quartz crystals are worn by some as pendants
for good luck.Quartz specimens are also very popular among collectors.Certain collectors specialize their entire collection on
different types of Quartz.Quartz occurs in virtually all mineral environments, and may be associated with almost
every mineral.Brilliant, doubly terminated crystals come from Middleville and
Little Falls, Herkimer Co.It is a scientific oddity why Rose Quartz so infrequently
forms crystals.Almost all Rose Quartz is massive, and fine crystals are quite rare.Black Hills of South Dakota
(near Custer, Custer Co.Fine Smoky Quartz comes from the Pikes Peak area, El Paso
Co.The world's premier software reference source.Just copy the HTML code fragment provided below to create the link and then paste it within your web content.For more details about this feature, visit our Webmaster and Blogger Tools page.Note: If no ads are returned, you could show your own ads.UNIT, THEN SKIP THAT MANY BEFORE REQUESTING ADS FOR THE SECOND UNIT.For text ads, append each ad to the string.More from Britannica on "quartz"...No distinct boundary exists between smoky and colourless quartz.Its abundance causes it to be worth considerably less than either amethyst or citrine.Its milky aspect is attributed to tiny needlelike inclusions of rutile, which, when ...Quartz monzonite differs from granodiorite by containing more alkali feldspar, usually more biotite and less ...Student Encyclopedia Britannica articles, specially written for elementary and high school studentsquartz The two most common chemical elements in the Earth's crust, oxygen and silicon, combine to form the mineral quartz, the second most abundant mineral after feldspar.Quartz has the chemical formula SiO2.There are many varieties of quartz.Quartz crystals for watches were developed shortly afterward.When a tiny quartz crystal is subjected to an alternating electric field, it produces an extremely steady ...The most common component of sand is quartz.This is because quartz is abundant, hard, nearly insoluble in water, and resistant to chemical decay (see Quartz).Other sands are made up of feldspar, calcareous material, iron ore, and volcanic glass.Quartz sands usually contain a small quantity of ...The natural abrasives in common use are emery, sandstone, and quartz.Binders commonly used for grinding wheels are clay, sodium silicate, and resins.It differs from agate in the flatness of its layers.There are many varieties of onyx.Quartz is a very common mineral.These are polished quartz pebbles.When pieces of quartz are tumbled, they take a very high
polish.This is a polished quartz sphere.Quartz is very hard and very common.Rose Quartz is pink in color, probably caused by
trace amounts of manganese or titanium.The Ancients believed that Rose Quartz
helped women have beautiful complexions and prevented wrinkles.They are actually doubly terminated quartz
crystals.Herkimer diamond in a vug.Quartz is composed primarily of silica (SiO2).The word crystal is derived from a Greek word meaning clear ice.This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than good mechanical movements.Generally, some form of digital logic counts the cycles of this signal and provides a numeric time display, usually in units of hours, minutes, and seconds.Quartz
Chemically, quartz is a compound called silicon dioxide.When a crystal of quartz is properly cut and mounted, it can be made to bend in an electric field.This property is known as piezoelectricity.Many materials can be formed into plates that will resonate.However, since quartz can be directly driven by an electric signal, no additional speaker or microphone is required.Quartz has the further advantage that it does not change size much as temperature changes.Fused quartz is often used for laboratory equipment that must not change shape as the temperature changes.This means that a quartz plate's size will not change much with temperature.This means that a quartz clock will be relatively accurate as the temperature changes.This frequency is equal to 215 Hz.In most clocks, the resonator is in a small can or flat package, about 4 mm long.Quartz Analog), or a liquid crystal display (LCD Digital).Hz, which is approximately 215, or 32,768 Hz.C: that is, a typical quartz wristwatch will gain or lose less than a half second per day at body temperature.If a quartz wristwatch is "rated" by measuring it against an atomic clock's time broadcast, and the wristwatch is worn on one's body to keep its temperature constant, then the corrected time will easily be accurate within 10 seconds per year.This is more than adequate to perform celestial navigation.That is, rather than just counting vibrations, their computer program takes the simple count, and scales it using a ratio calculated between an epoch set at the factory, and the most recent time the clock was set.These clocks usually have special instructions for changing the battery (the counter must not be permitted to stop), and become more accurate as they grow older.It is possible for a computerized clock to measure its temperature, and adjust for that as well.Chronometers
Quartz chronometers designed as time standards often include a crystal oven, to keep the crystal at a constant temperature.The piezoelectric properties of quartz were discovered by Jacques and Pierre Curie in 1880.The first quartz crystal oscillator was built by Walter G.In 1927 the first quartz clock was built by Warren Marrison and J.Horton at Bell Telephone Laboratories in Canada.The next 3 decades saw the development of quartz clocks as precision time standards in laboratory settings; the bulky delicate counting electronics, built with vacuum tubes, limited their use elsewhere.In 1932 a quartz clock was able to measure tiny weekly variations in the rotation rate of the Earth.The National Bureau of Standards (now NIST) based the time standard of the US on quartz clocks between the 1930s and the 1960s, when it went to atomic clocks.The wider use of quartz clock technology had to await the development of cheap semiconductor digital logic in the 60s.In 1969, Seiko produced the world's first quartz wristwatch, the Astron.The inherent accuracy and low cost of production has resulted in the proliferation of quartz clocks and watches since that time.By the 1980s quartz technology had taken over applications such as kitchen timers, alarm clocks, bank vault time locks, and time fuzes on munitions, from earlier mechanical balance wheel movements.Quartz timepiece production has emerged from Asia, notably Hong Kong and Japan.Quartz wristwatches are in high demand today as they are more accurate than their mechanical brothers; they need neither winding nor much maintenance.Itoh H, Aoshima Y, Sakaguchi Y (2002)."The Evolution of the Quartz Crystal Clock".Time and Frequency Division, National Institute of Standards and Technology.From the roots until today's achievements...."Time and the Royal Society"."The Evolution of the quartz crystal clock".This page was last modified 23:12, 1 February 2008.All text is available under the terms of the GNU Free Documentation License.Quartz
Quartz is thought to have come from the German miner's language of the Middle Ages, but the original meaning is not known.The sides of the crystal are marked with crosswise striations (ridges).Quartz comes in a wide range of colors.Most quartz crystals are not used as gemstones, but as raw materials in industry.Quartz crystals are piezoelectric, and are used in watches, radios, oscillators, and wave stabilizers.Silicon and oxygen, the two most common chemical elements in the Earth's crust, combine as silicon dioxide to form the mineral quartz.Quartz is the most abundant mineral in the Earth's crust.Quartz has the chemical formula SiO2.There are many varieties of quartz, which occurs in nearly all types of igneous, metamorphic and sedimentary rocks.It is an essential mineral in granites, granodiorites and rhyolites.Quartz is very resistant to weathering and, therefore, concentrates as sandstones and other detrital rocks.Most sands are weathered fragments of quartz.Quartz has many commercial applications.In science and industry, quartz sand is used for manufacturing sandpaper and other abrasives, polishing powders and soaps.Quartz sand is also used in the manufacture of porcelain, glass and metal casting molds.Silica glass (fused quartz) is used in optics to transmit ultraviolet light and to make laboratory tubing and vessels, as well as fibers employed in sensitive weighing devices.Compositionally, quartz is usually quite pure, with only traces of other elements like aluminum, sodium, potassium and lithium.The many varieties of quartz is due to formation of different geometric arrangements of its tetrahedral crystals.This account for different crystal structures, and, therefore, different physical properties.Many of the quartz variations listed below are gemstones.
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