Welcome Mineralogy Silica Group Quartz Silica Group Earths

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Mineralogy Silica Group

Quartz

Silica Group �Earth’s crust consists of about 95% of silicate minerals (60% of Feldspar & 12% of Quartz) �Silica occurs in seven distinct forms in nature, among quartz is the most common mineral and occurs in large amount. �Quartz (Si. O 2) crystals commonly appear prismatic with two sets of rhombohedrons.

Silica Group �Color – Pure quartz is colorless, can occur any shaded. Some variety of quartz white, rose, red, grey, violet, brown shade. �Streak – Colourless, white �Cleavage – Absent �Fracture – Uneven, subconcoidal

Silica Group �Specific Gravity – 2. 65 to 2. 8 �Lustre – Vitreous, subvitreous �Other property – Piezoelectric �Diagnostic features – Quartz is generally recognized by its crystal form, hardness and lake of cleavage.

Varieties of Quartz �Rock crystal – Colourless, transparent �Amethyst – Violet or purple color and used as ornaments and consider as semiprecious stone. �Rose quartz – Rose color �Milky quartz – A common variety, milkyness is due to the presence of air cavity.

Varieties of Quartz �Smoky quartz – Smoky-yellow or smoky-brown color �Chalcedony – Uniform light color �Agate – Banded form of chalcedony used as ornaments.

Varieties of Quartz �Jasper – Red or brown color colloidal of iron oxide particles. �Flint or Chert �Silicified wood

by-nc-nd: Helmetti by-nc-nd: Orbital Joe by-nc-nd: oldbones rose quartz opal: rough and polished Quartz by other names: amethyst tiger’s eye by-nc-sa: jspace 3 citrine chalcedony by-nc-nd: Future-Ph. D. by-nc-nd: oldbones by: jaja_1985 agate

Occurrence �Abundantly occur in crystal layers of the earth. �Quartz occur as veins or reegs �Original constituents of acid igneous rocks such as granite, rhyolites �It is detrital mineral in sandstone �Metamorhic rocks also consist of quartz.

Mineral Resources �India has largest and extensive deposits of quartz and silica sand. �These minerals available in AP, BH, DL, GJ, KA, KL, MP, MH, OR, RJ, TN and UP

Industrial Uses �Rock crystals or pure quartz used as controlling the frequency of electrical impulses. �When the quartz crystal are subject to direct pressure positive and negative charges develop at the two ends. �Quartz plate used in controlling frequency in radio circuits.

Pure quartz crystals are piezoelectric – that means that when put under pressure, the crystal produces an electric voltage. by-sa: threedots by-nc-nd: jwinfred This characteristic allows quartz crystals to be used to measure pressures or control the frequency of electric impulses, which led to their use in radio systems and timepieces.

Industrial Uses �Fibre-quartz wires are presently transmission of telephone message. used for �Quartz crystals cut into prisms are used as quartz wedge and lenses in petrological microscope. �Quartz and silica sand are commonly used in the manufacturing of glass.

Quartz is used in the manufacture of glass by-sa: bongo vongo by-nc-nd: gsgeorge by-nd: savinca by-nc-sa: Rob Ireton

Industrial Uses �Pure sand is used in manufacturing sand paper and abrasive cloth. �Pure silica sand is used in ceramics. �Silicon-carbide used in grinding wheels and is used for automobile spare parts, engine, aircraft.

by-nc: bombelek by-sa: Ebua Libana by-nc: birdfarm by-nc-sa: amortize Quartz is mixed with clay and ground-up feldspar, and then fired to form a wide range of ceramic and porcelain products.

Industrial Uses �Quartz is also used in the preparation of activated silica for absorption of water moisture. �Activated silica is used for drying of paints. �Agate minerals are used in ornamental and semiprecious stone.

by-sa: Southern_Comfort by-nc-sa: BBColin Quartz is used as a flux for metallurgy. A flux is a material that melts easily and can be used to remove impurities from metal ores, or that makes the slag produced by metal ore smelting more fluid.

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