Natural Elestial Quartz Crystal Top Ungeschliffener Bergkristall Quarz Brasilien

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Seller: classicrocksandgems2 ✉️ (5,419) 100%, Location: Morsbach, DE, Ships to: WORLDWIDE, Item: 161571390273 Natural Elestial Quartz Crystal Top Ungeschliffener Bergkristall Quarz Brasilien. Dieser Elestial Quartz Kristall wurde sorgfältig selectiert  Er ist von Top Qualität ungeschliffen und ohne Beschädigungen an den Spitzen  Herkunft : Aracuai MG Brasilien               Gewicht : 316 gr                Größe : 91 x 89.9 x 53 mm ************************ This quartz crystal has been carefully selected Top quality with no damage on the points , natural and unpolished Origin : Aracuai MG Brazil                  Weight : 316 gr                   Size : 91 x 89.9 x 53 mm

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"Elestial quartz" ("heavenly quartz") is a term that apparently came up with the esoteric renaissance. It is not a very well defined term, and very often confused with other (rather strictly defined) growth forms. Often it is used as a synonym of "Jacaré Quartz", (also known as Crocodile or  Alligator Quartz ).

An idealized definition might be: elestial quartz is a quartz that has small crystals grown on the rhombohedral faces of a greater crystal. Since the smaller crystals grew as a continuation of the crystal lattice of the underlying greater crystal, their rhombohedral faces are all oriented in parallel. In a sense, it is a multiple scepter quartz. As some people seem to get it wrong, it should be stressed that such a pattern cannot be caused solely by natural etching of a crystal, it is a  growth  form. However, such a growth could be triggered by the surface structure of a formerly etched underlying crystal., an elestial smoky quartz from Minas Gerais, Brazil. It likely came from a pegmatite,

It is the parallel arrangement of triangular crystal faces that inspired its naming: "Jacaré" means alligator in Portuguese, referring to the similar pattern seen on the back of an alligator.

Text : quartzpage.de

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The word "quartz" is derived from the German word "Quarz" and its Middle High German ancestor "twarc", which probably originated in Slavic (cf. Czech tvrdý ("hard"), Polish twardy ("hard")) Naturally occurring quartz crystals of extremely high purity, necessary for the crucibles and other equipment used for growing silicon wafers in the semiconductor industry, are expensive and rare. A major mining location for high purity quartz is the Spruce Pine Gem Mine in Spruce Pine, North Carolina, United States.

The largest documented single crystal of quartz was found near Itapore, Goiaz, Brazil; it measured approximately 6.1×1.5×1.5 m and weighed more than 44 tonnes.

Quartz is a very common mineral, a chemical compound of silicon and oxygen, silicon dioxide SiO2, commonly called silica. If pure, quartz is a colorless, transparent, and very hard crystalline material of glass-like look. The well-known rock crystals - six-sided prisms with a six-sided pyramid at their ends - are simply well formed crystals of quartz. The word "Quarz" (the "t" is missing on purpose) is known from European literature on mining dating back to the 14th century. It is probably of German or Slavic origin. Quartz crystals occur in a great number of different shapes. Most rockhounds are familiar with their look and immediately recognize quartz crystals, so despite the great number of varieties and growth forms, all quartz crystals share some characteristics. Whatever the shape of a quartz crystal, the angles between the faces never change. Quartz crystals lack mirror symmetry. The mirror image of a quartz crystal is different from the original image, no matter where the mirror plane lies.

Instead, quartz crystals show handedness: there are 2 types of crystals, left-handed and right-handed crystals. This is very similar to the human hand - you have a left and right hand. Each of them is a mirror image of the other, but the mirror image of the left hand is not a left hand, so each hand itself lacks internal mirror symmetry (unlike the human face, for example, which is roughly mirror symmetric). Quite frequently one can find crystals that apparently do not obey the rules and show s- and x-crystal faces at unusual positions. For example, they show x-faces to the left and to the right of an r-face, making it impossible to classify the crystal as left- or right-handed. These crystals are twinned, that is, they consist of two or more crystals that are intergrown in a law-like manner. Quartz shows 3 types of twinning (twinning laws), and the 2 more common ones look very unsuspicious to the uninitiated. In contrast to many other minerals, most quartz crystal twins are not made of two clearly identifiable crystals, but simply a single crystal that ideally looks like the intersection of two crystals. A crystal is said to be twinned if it is composed of 2 or more crystal subindividuals whose crystal lattices are oriented differently but nevertheless are intergrown in a law-like, specific manner. The subindividuals are not just put together at an arbitrary angle; they share atoms along their border. For this to be possible the border always corresponds to a specific crystal form: it cuts the crystal lattice of the subindividuals at the same respective angles, and the subindividuals touch each other as if two separate crystals touched each other with identical crystal faces. The virtual plane that corresponds to these crystal faces is called the composition plane. "Crystal habit" refers to the overall shape of the crystal, leaving aside its inner structure. The crystal habit can be described in obvious terms like "barrel-like", "needle-like", "elongated", or "short-prismatic". However, the notion of crystal habit also includes less obvious terms as "trigonal habit" or terms which are specific to individual minerals, like "Dauphiné habit". The habit of a crystal is dependent on the relative sizes of crystal faces. For example, the dominance of certain forms on a quartz crystal might cause a cube-like look that is accordingly called "pseudo-cubic habit". Growth inhibition in quartz is usually associated with crystals of other minerals that got in the way of a growing crystal and were later dissolved, but the most common case is that of crystals that were literally running out of space during growth.

Text : quartzpage.de

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Quartz
Quartz
Quartz crystal cluster from Tibet
General
CategorySilicate mineral
Formula (repeating unit) SiO2
Strunz classification 04.DA.05
Dana classification75.01.03.01
Crystal symmetry Trigonal 32
Unit cell a = 4.9133 Å , c = 5.4053 Å; Z=3
Identification
ColorColorless through various colors to black
Crystal habit 6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive
Crystal system α-quartz: trigonal trapezohedral class 3 2; β-quartz: hexagonal 622[1]
Twinning Common Dauphine law, Brazil law and Japan law
Cleavage {0110} Indistinct
Fracture Conchoidal
TenacityBrittle
Mohs scale hardness7 – lower in impure varieties (defining mineral)
Luster Vitreous – waxy to dull when massive
Streak White
Diaphaneity Transparent to nearly opaque
Specific gravity 2.65; variable 2.59–2.63 in impure varieties
Optical propertiesUniaxial (+)
Refractive index nω = 1.543–1.545 nε = 1.552–1.554
Birefringence +0.009 (B-G interval)
Pleochroism None
Melting point 1670 °C (β tridymite ) 1713 °C (β cristobalite )[1]
Solubility Insoluble at STP ; 1 ppmmass at 400 °C and 500 lb/in2 to 2600 ppmmass at 500 °C and 1500 lb/in2[1]
Other characteristicsPiezoelectric , may be triboluminescent , chiral (hence optically active if not racemic)
References[2] [3] [4] [5]

Quartz is the second most abundant mineral in the Earth 's continental crust , after feldspar . It is made up of a continuous framework of SiO4 silicon –oxygen tetrahedra , with each oxygen being shared between two tetrahedra, giving an overall formula SiO2 .

There are many different varieties of quartz, several of which are semi-precious gemstones . Especially in Europe and the Middle East, varieties of quartz have been since antiquity the most commonly used minerals in the making of jewelry and hardstone carvings .

Contents  [hide ] 
  • 1 Etymology
  • 2 Crystal habit and structure
  • 3 Varieties (according to color)
    • 3.1 Citrine
    • 3.2 Rose quartz
    • 3.3 Amethyst
    • 3.4 Smoky quartz
    • 3.5 Milky quartz
  • 4 Varieties (according to microstructure)
  • 5 Synthetic and artificial treatments
  • 6 Occurrence
  • 7 Related silica minerals
  • 8 History
  • 9 Piezoelectricity
  • 10 Gallery of quartz mineral specimens
  • 11 See also
  • 12 References
  • 13 External links

The word "quartz" is derived from the German word "Quarz" and its Middle High German ancestor "twarc", which probably originated in Slavic (cf. Czech tvrdý ("hard"), Polish twardy ("hard")).[6]

Crystal habit and structure Crystal structure of α-quartz β-quartz

Quartz belongs to the trigonal crystal system . The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end. In nature quartz crystals are often twinned , distorted, or so intergrown with adjacent crystals of quartz or other minerals as to only show part of this shape, or to lack obvious crystal faces altogether and appear massive. Well-formed crystals typically form in a 'bed' that has unconstrained growth into a void; usually the crystals are attached at the other end to a matrix and only one termination pyramid is present. However doubly-terminated crystals do occur where they develop freely without attachment, for instance within gypsum . A quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward.

α-quartz crystallizes in the trigonal crystal system, space group P 3121 and P 3221 respectively. β-quartz belongs to the hexagonal system, space group P 6222 and P 6422, respectively.[7] These space groups are truly chiral (they each belong to the 11 enantiomorphous pairs). Both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks (SiO4 tetrahedra in the present case). The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, without change in the way they are linked.

Varieties (according to color) Figurine of a child carved in rock crystal, hittite , between 1500 and 1200 BC

Pure quartz, traditionally called rock crystal (sometimes called clear quartz ), is colorless and transparent (clear) or translucent, and has often been used for hardstone carvings , such as the Lothair Crystal . Common colored varieties include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others. Quartz goes by an array of different names. The most important distinction between types of quartz is that of macrocrystalline (individual crystals visible to the unaided eye) and the microcrystalline or cryptocrystalline varieties (aggregates of crystals visible only under high magnification). The cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline. Chalcedony is a cryptocrystalline form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite .[8] Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate , sard , onyx , carnelian , heliotrope , and jasper .

Citrine Citrine "Citrine" redirects here. For other uses, see Citrine (disambiguation) .

Citrine is a variety of quartz whose color ranges from a pale yellow to brown due to ferric impurities. Natural citrines are rare; most commercial citrines are heat-treated amethysts or smoky quartzes . However, a heat-treated amethyst will have small lines in the crystal, as opposed to a natural citrine's cloudy or smokey appearance. It is nearly impossible to tell cut citrine from yellow topaz visually, but they differ in hardness.Brazil is the leading producer of citrine, with much of its production coming from the state of Rio Grande do Sul . The name is derived from Latin citrina which means "yellow" and is also the origin of the word "citron." Sometimes citrine and amethyst can be found together in the same crystal, which is then referred to as ametrine .[9]

Rose quartz An elephant carved in rose quartz, 10 cm (4 inches) long

Rose quartz is a type of quartz which exhibits a pale pink to rose red hue. The color is usually considered as due to trace amounts of titanium , iron , or manganese , in the massive material. Some rose quartz contains microscopic rutile needles which produces an asterism in transmitted light. Recent X-ray diffraction studies suggest that the color is due to thin microscopic fibers of possibly dumortierite within the massive quartz.[10]

Additionally, there is a rare type of pink quartz (also frequently called crystalline rose quartz) with color that is thought to be caused by trace amounts of phosphate or aluminium . The color in crystals is apparently photosensitive and subject to fading. The first crystals were found in a pegmatite found near Rumford , Maine , USA, but most crystals on the market come from Minas Gerais , Brazil .[11]

Amethyst Amethyst Guerrero, Mexico Main article: Amethyst

Amethyst is a popular form of quartz that ranges from a bright to dark or dull purple color. The world's largest deposits of amethysts can be found in Brazil, Mexico, Uruguay, Russia, France, Namibia and Morocco. Sometimes amethyst and citrine are found growing in the same crystal. It is then referred to as ametrine . An amethyst is formed when there is iron in the area where it was formed.

Smoky quartz Main article: Smoky quartz Smoky quartz .

Smoky quartz is a gray, translucent version of quartz. It ranges in clarity from almost complete transparency to a brownish-gray crystal that is almost opaque. Some can also be black.

Milky quartz Milky quartz sample Ancient Roman cameo onyx engraved gem of Augustus

Milk quartz or milky quartz may be the most common variety of crystalline quartz and can be found almost anywhere. The white color may be caused by minute fluid inclusions of gas, liquid, or both, trapped during the crystal formation. The cloudiness caused by the inclusions effectively bars its use in most optical and quality gemstone applications.[12]

Varieties (according to microstructure)

Although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is a secondary identifier for the cryptocrystalline minerals, although it is a primary identifier for the macrocrystalline varieties. This does not always hold true.[clarification needed ]

Major varieties of quartz
Chalcedony Cryptocrystalline quartz and moganite mixture. The term is generally only used for white or lightly colored material. Otherwise more specific names are used.
Agate Multi-colored, banded chalcedony, semi-translucent to translucent
Onyx Agate where the bands are straight, parallel and consistent in size.
Jasper Opaque cryptocrystalline quartz, typically red to brown
Aventurine Translucent chalcedony with small inclusions (usually mica) that shimmer.
Tiger's eye Fibrous gold to red-brown colored quartz, exhibiting chatoyancy .
Rock crystal Clear, colorless
Amethyst Purple, transparent
Citrine Yellow to reddish orange to brown, greenish yellow
Prasiolite Mint green, transparent
Rose quartz Pink, translucent, may display diasterism
Rutilated quartz Contains acicular (needle-like) inclusions of rutile
Milky quartz White, translucent to opaque, may display diasterism
Smoky quartz Brown to gray, opaque
Carnelian Reddish orange chalcedony, translucent
Dumortierite quartz Contains large amounts of dumortierite crystals

Synthetic and artificial treatments A synthetic quartz crystal grown by the hydrothermal method , about 19 cm long and weighing about 127 grams

Not all varieties of quartz are naturally occurring. Some clear quartz crystals can be treated using heat or gamma-irradiation to induce color where it would not otherwise have occurred naturally. Susceptibility to such treatments depends on the location from which the quartz was mined.[13] Prasiolite , an olive colored material, is produced by heat treatment; natural prasiolite has also been observed in Lower Silesia in Poland. Although citrine occurs naturally, the majority is the result of heat-treated amethyst. Carnelian is widely heat-treated to deepen its color.

Because natural quartz is often twinned , synthetic quartz is produced for use in industry. Large, flawless, single crystals are synthesized in an autoclave via the hydrothermal process ; emeralds are also synthesized in this fashion.

Occurrence

Quartz is an essential constituent of granite and other felsic igneous rocks . It is very common in sedimentary rocks such as sandstone and shale and is also present in variable amounts as an accessory mineral in most carbonate rocks . It is also a common constituent of schist , gneiss , quartzite and other metamorphic rocks . Because of its resistance to weathering it is very common in stream sediments and in residual soils . Quartz, therefore, occupies the lowest potential to weather in the Goldich dissolution series .

While the majority of quartz crystallizes from molten magma , much quartz also chemically precipitates from hot hydrothermal veins as gangue , sometimes with ore minerals like gold, silver and copper. Large crystals of quartz are found in magmatic pegmatites . Well-formed crystals may reach several meters in length and weigh hundreds of kilograms.

Naturally occurring quartz crystals of extremely high purity, necessary for the crucibles and other equipment used for growing silicon wafers in the semiconductor industry, are expensive and rare. A major mining location for high purity quartz is the Spruce Pine Gem Mine in Spruce Pine, North Carolina , United States .[14]

The largest documented single crystal of quartz was found near Itapore, Goiaz, Brazil; it measured approximately 6.1×1.5×1.5 m and weighed more than 44 tonnes .[15]

Related silica minerals

Tridymite and cristobalite are high-temperature polymorphs of SiO2 that occur in high-silica volcanic rocks. Coesite is a denser polymorph of quartz found in some meteorite impact sites and in metamorphic rocks formed at pressures greater than those typical of the Earth's crust. Stishovite is a yet denser and higher-pressure polymorph of quartz found in some meteorite impact sites. Lechatelierite is an amorphous silica glass SiO2 which is formed by lightning strikes in quartz sand .

History Fatimid carved rock crystal (clear quartz) vase, c. 1000 Quartz crystal demonstrating transparency

The word "quartz" comes from the German  Quarz