This article is about the mineral. For other uses, see Quartz (disambiguation)
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.[10]
Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at 573 °C (846 K; 1,063 °F). Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold.
There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Europe and Asia.
Quartz is the mineral defining the value of 7 on the Mohs scale of hardness, a qualitative scratch method for determining the hardness of a material to abrasion.
Etymology
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The word "quartz" is derived from the German word Quarz,[11] which had the same form in the first half of the 14th century in Middle High German and in East Central German[12] and which came from the Polish dialect term kwardy, which corresponds to the Czech term tvrdý ("hard").[13] Some sources, however, attribute the word's origin to the Saxon word Querkluftertz, meaning cross-vein ore.[14][15]
The Ancient Greeks referred to quartz as κρύσταλλος (krustallos) derived from the Ancient Greek κρύος (kruos) meaning "icy cold", because some philosophers (including Theophrastus) understood the mineral to be a form of supercooled ice.[16] Today, the term rock crystal is sometimes used as an alternative name for transparent coarsely crystalline quartz.[17][18]
Early studies
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Roman naturalist Pliny the Elder believed quartz to be water ice, permanently frozen after great lengths of time.[19] He supported this idea by saying that quartz is found near glaciers in the Alps, but not on volcanic mountains, and that large quartz crystals were fashioned into spheres to cool the hands. This idea persisted until at least the 17th century. He also knew of the ability of quartz to split light into a spectrum.[20]
In the 17th century, Nicolas Steno's study of quartz paved the way for modern crystallography. He discovered that regardless of a quartz crystal's size or shape, its long prism faces always joined at a perfect 60° angle.[21]
Crystal habit and structure
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Crystal structure of α-quartz (red balls are oxygen, grey are silicon)
Crystal structure of β-quartz
A chiral pair of α-quartz
Quartz belongs to the trigonal crystal system at room temperature, and to the hexagonal crystal system above 573 °C (846 K; 1,063 °F). The ideal crystal shape is a six-sided prism terminating with six-sided pyramid-like rhombohedrons at each end. In nature, quartz crystals are often twinned (with twin right-handed and left-handed quartz crystals), 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 as a druse (a layer of crystals lining a void), of which quartz geodes are particularly fine examples.[24] The crystals are attached at one end to the enclosing rock, and only one termination pyramid is present. However, doubly terminated crystals do occur where they develop freely without attachment, for instance, within gypsum.[25]
α-quartz crystallizes in the trigonal crystal system, space group P3121 or P3221 (space group 152 or 154 resp.) depending on the chirality. Above 573 °C (846 K; 1,063 °F), α-quartz in P3121 becomes the more symmetric hexagonal P6422 (space group 181), and α-quartz in P3221 goes to space group P6222 (no. 180).[26]
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 a change in the way they are linked. However, there is a significant change in volume during this transition,[clarification needed] and this can result in significant microfracturing in ceramics[28] and in rocks of the Earth's crust.[29]
Sceptered quartz
Sceptered quartz (as aggregates: "Elestial quartz")
Prismatic quartz with black hematite
Druse quartz
Granular quartz
Twinned quartz
Massive quartz
Varieties (according to microstructure)
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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.[30]
Varieties (according to color)
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Quartz crystal demonstrating transparencyPure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent 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.[31] These color differentiations arise from the presence of impurities which change the molecular orbitals, causing some electronic transitions to take place in the visible spectrum causing colors.
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.[32] Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate, carnelian or sard, onyx, heliotrope, and jasper.
Amethyst
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Rock crystal
Amethyst
Blue quartz
Dumortierite quartz
Citrine quartz (natural)
Citrine quartz (heat-altered amethyst)
Milky quartz
Rose quartz
Smoky quartz
Prase
Amethyst is a form of quartz that ranges from a bright vivid violet to a dark or dull lavender shade. 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. Amethyst derives its color from traces of iron in its structure.[33]
Blue quartz
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Blue quartz contains inclusions of fibrous magnesio-riebeckite or crocidolite.[34]
Dumortierite quartz
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Inclusions of the mineral dumortierite within quartz pieces often result in silky-appearing splotches with a blue hue. Shades of purple or grey sometimes also are present. "Dumortierite quartz" (sometimes called "blue quartz") will sometimes feature contrasting light and dark color zones across the material.[35][36] "Blue quartz" is a minor gemstone.[35][37]
Citrine
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Citrine is a variety of quartz whose color ranges from pale yellow to brown due to a submicroscopic distribution of colloidal ferric hydroxide 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 smoky appearance. It is nearly impossible to differentiate between cut citrine and 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 the Latin word 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.[39] Citrine has been referred to as the "merchant's stone" or "money stone", due to a superstition that it would bring prosperity.[40]
Citrine was first appreciated as a golden-yellow gemstone in Greece between 300 and 150 BC, during the Hellenistic Age. Yellow quartz was used prior to that to decorate jewelry and tools but it was not highly sought after.[41]
Milky quartz
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Milk quartz or milky quartz is the most common variety of crystalline quartz. The white color is caused by minute fluid inclusions of gas, liquid, or both, trapped during crystal formation,[42] making it of little value for optical and quality gemstone applications.[43]
Rose quartz
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Rose quartz is a type of quartz that 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 material. Some rose quartz contains microscopic rutile needles that produce asterism in transmitted light. Recent X-ray diffraction studies suggest that the color is due to thin microscopic fibers of possibly dumortierite within the quartz.[44]
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, US, and in Minas Gerais, Brazil.[45] The crystals found are more transparent and euhedral, due to the impurities of phosphate and aluminium that formed crystalline rose quartz, unlike the iron and microscopic dumortierite fibers that formed rose quartz.[46]
Smoky quartz
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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. The translucency results from natural irradiation acting on minute traces of aluminum in the crystal structure.[47]
Prase
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Prase is a green variety of quartz.[48] The green color is caused by inclusions of amphibole.[49]
Prasiolite
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Not to be confused with Praseolite
Prasiolite, also known as vermarine, is a variety of quartz that is green in color.[50] The green is caused by iron ions.[49] It is a rare mineral in nature and is typically found with amethyst; most "prasiolite" is not natural – it has been artificially produced by heating of amethyst. Since 1950[citation needed], almost all natural prasiolite has come from a small Brazilian mine, but it is also seen in Lower Silesia in Poland. Naturally occurring prasiolite is also found in the Thunder Bay area of Canada.[50]
Piezoelectricity
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Quartz crystals have piezoelectric properties; they develop an electric potential upon the application of mechanical stress.[51] Quartz's piezoelectric properties were discovered by Jacques and Pierre Curie in 1880.[52][53]
Occurrence
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Granite rock in the cliff of Gros la Tête on Aride Island, Seychelles. The thin (1–3 cm wide) brighter layers are quartz veins, formed during the late stages of crystallization of granitic magmas. They are sometimes called "hydrothermal veins".Quartz is a defining constituent of granite and other felsic igneous rocks. It is very common in sedimentary rocks such as sandstone and shale. It is a common constituent of schist, gneiss, quartzite and other metamorphic rocks. Quartz has the lowest potential for weathering in the Goldich dissolution series and consequently it is very common as a residual mineral in stream sediments and residual soils. Generally a high presence of quartz suggests a "mature" rock, since it indicates the rock has been heavily reworked and quartz was the primary mineral that endured heavy weathering.[54]
While the majority of quartz crystallizes from molten magma, 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.[55]
The largest documented single crystal of quartz was found near Itapore, Goiaz, Brazil; it measured approximately 6.1 m × 1.5 m × 1.5 m and weighed 39,916 kilograms.[56]
Mining
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Quartz is extracted from open pit mines. Miners occasionally use explosives to expose deep pockets of quartz. More frequently, bulldozers and backhoes are used to remove soil and clay and expose quartz veins, which are then worked using hand tools. Care must be taken to avoid sudden temperature changes that may damage the crystals.[57][58]
Related silica minerals
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Tridymite and cristobalite are high-temperature polymorphs of SiO2 that occur in high-silica volcanic rocks. Coesite is a denser polymorph of SiO2 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 SiO2 found in some meteorite impact sites. Moganite is a monoclinic polymorph. Lechatelierite is an amorphous silica glass SiO2 which is formed by lightning strikes in quartz sand.[60]
Safety
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As quartz is a form of silica, it is a possible cause for concern in various workplaces. Cutting, grinding, chipping, sanding, drilling, and polishing natural and manufactured stone products can release hazardous levels of very small, crystalline silica dust particles into the air that workers breathe.[61] Crystalline silica of respirable size is a recognized human carcinogen and may lead to other diseases of the lungs such as silicosis and pulmonary fibrosis.[62][63]
Synthetic and artificial treatments
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A synthetic quartz crystal grown by the hydrothermal method, about 19 centimetres (7.5 in) long and weighing about 127 grams (4.5 oz)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.[64]
Prasiolite, an olive colored material, is produced by heat treatment;[65] natural prasiolite has also been observed in Lower Silesia in Poland.[66] Although citrine occurs naturally, the majority is the result of heat-treating amethyst or smoky quartz.[65] Carnelian has been heat-treated to deepen its color since prehistoric times.[67]
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.[68][69]
Like other crystals, quartz may be coated with metal vapors to give it an attractive sheen.[70][71]
Uses
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Quartz is the most common material identified as the mystical substance maban in Australian Aboriginal mythology. It is found regularly in passage tomb cemeteries in Europe in a burial context, such as Newgrange or Carrowmore in Ireland. Quartz was also used in Prehistoric Ireland, as well as many other countries, for stone tools; both vein quartz and rock crystal were knapped as part of the lithic technology of the prehistoric peoples.[72]
While jade has been since earliest times the most prized semi-precious stone for carving in East Asia and Pre-Columbian America, in Europe and the Middle East the different varieties of quartz were the most commonly used for the various types of jewelry and hardstone carving, including engraved gems and cameo gems, rock crystal vases, and extravagant vessels. The tradition continued to produce objects that were very highly valued until the mid-19th century, when it largely fell from fashion except in jewelry. Cameo technique exploits the bands of color in onyx and other varieties.
Efforts to synthesize quartz began in the mid-nineteenth century as scientists attempted to create minerals under laboratory conditions that mimicked the conditions in which the minerals formed in nature: German geologist Karl Emil von Schafhäutl (1803–1890) was the first person to synthesize quartz when in 1845 he created microscopic quartz crystals in a pressure cooker.[73] However, the quality and size of the crystals that were produced by these early efforts were poor.[74]
Elemental impurity incorporation strongly influences the ability to process and utilize quartz. 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. These high-purity quartz are defined as containing less than 50 ppm of impurity elements.[75] A major mining location for high purity quartz is the Spruce Pine Gem Mine in Spruce Pine, North Carolina, United States.[76] Quartz may also be found in Caldoveiro Peak, in Asturias, Spain.[77]
By the 1930s, the electronics industry had become dependent on quartz crystals. The only source of suitable crystals was Brazil; however, World War II disrupted the supplies from Brazil, so nations attempted to synthesize quartz on a commercial scale. German mineralogist Richard Nacken (1884–1971) achieved some success during the 1930s and 1940s.[78] After the war, many laboratories attempted to grow large quartz crystals. In the United States, the U.S. Army Signal Corps contracted with Bell Laboratories and with the Brush Development Company of Cleveland, Ohio to synthesize crystals following Nacken's lead.[79][80] (Prior to World War II, Brush Development produced piezoelectric crystals for record players.) By 1948, Brush Development had grown crystals that were 1.5 inches (3.8 cm) in diameter, the largest at that time.[81][82] By the 1950s, hydrothermal synthesis techniques were producing synthetic quartz crystals on an industrial scale, and today virtually all the quartz crystal used in the modern electronics industry is synthetic.[69]
An early use of the piezoelectricity of quartz crystals was in phonograph pickups. One of the most common piezoelectric uses of quartz today is as a crystal oscillator. The quartz oscillator or resonator was first developed by Walter Guyton Cady in 1921.[83][84] George Washington Pierce designed and patented quartz crystal oscillators in 1923.[85][86][87] The quartz clock is a familiar device using the mineral. Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in 1927.[88] The resonant frequency of a quartz crystal oscillator is changed by mechanically loading it, and this principle is used for very accurate measurements of very small mass changes in the quartz crystal microbalance and in thin-film thickness monitors.[89]
Almost all the industrial demand for quartz crystal (used primarily in electronics) is met with synthetic quartz produced by the hydrothermal process. However, synthetic crystals are less prized for use as gemstones.[91] The popularity of crystal healing has increased the demand for natural quartz crystals, which are now often mined in developing countries using primitive mining methods, sometimes involving child labor.[92]
See also
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References
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Quartz is a crystal of a thousand colors, shapes and varieties. Blue, pink, purple, white, green types of quartz are used to create beautiful colored jewels, to make watches, lamps, digital appliances, light bulbs, bathroom furniture and much more also thanks to its physical properties very useful in the industrial field. Some varieties of quartz rock are transparent like a piece of ice. Hence, quartz meaning, according to some scholars, comes from ancient Greek word “krýstallos“, that is, precisely, ice: in fact, they thought that quartz was a kind of ice that, for some reason, could no longer melt and become water again; belief deriving from the fact that clear quartz in addition to being cold to the touch, also resembled snowflakes in its structure. There are many legends and stories that revolve around precious quartz stone: many ancient peoples believed that quartz had magical and even therapeutic properties. In short, quartz has a history that has its roots in prehistoric times: our ancestors used it to build knives, axes, cutting tools and tips for arrows and spears, as well as to create jewels, pendants and precious amulets of various kinds, even used during religious ceremonies.
Characteristics of quartz
Quartz is one of the most widespread and common minerals in the earth’s crust which is mined in many areas of the world. It is very common to find quartz rock on the banks of rivers and lakes or along the slopes of volcanoes following a crystallization process during the cooling of lava material. Quartz is one of the main elements that make up many types of rocks, namely igneous, sedimentary and metamorphic ones. From a chemical point of view, quartz stone corresponds to silicon dioxide (SiO2), that is formed by the combination of one part of silicon and two parts of oxygen that form tetrahedrons and are divided into three categories: macrocrystalline quartz when crystals quartz are visible to the naked eye (like rose quartz); microcrystalline quartz when crystals quartz can only be seen under the microscope (such as jade) and cryptocrystalline quartz when crystals quartz are not even seen under a microscope (such as chalcedony). Clear quartz has a density of 2.65 g/cm3 and from a thermal point of view it has a stable shape below 573 °C. Quartz is a hard mineral that on the Mohs scale measures 7, while the diamond 9, and is therefore harder than metal. Clear quartz has a vitreous and reflective luster and, in its purest form, it is transparent, clear and colorless and often, depending on the geological zone in which it is located, can contain gaseous, solid and liquid inclusions.
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From a crystallographic point of view, quartz has a trigonal lattice and has a six-sided bipyramidal prism-shaped habitus but it is very rare to find it in this form and is generally found as small grains within metamorphic and magmatic rocks. However, quartz stone can also be in the shape of an elongated prism. Among its most important properties and characteristics, quartz has a remarkable stability and is resistant to any type of acid, except hydrofluoric acid. Furthermore, it is resistant to heat and breakage and it is piezoelectric, which means that it can electrically polarize its opposite faces after a process of mechanical deformation caused by heating or compression.
Quartz colors
Since it is one of the most widespread minerals in the world, quartz has, depending on the geological zone of formation, a crystalline structure and different mineralogical and chemical characteristics, with numerous shades of quartz color. When pure, clear quartz is completely transparent and colorless. When it has impurities, defects or inclusions of other rocks and minerals, this mineral begins to take on different quartz colors. Carnelian, a particular type of red chalcedony, for example, takes on this color due to the presence of iron oxides inside, as does amethyst which has a more or less transparent color tending to purplish; green quartz which contains lamellar inclusions or like jasper which is opaque and very colored due to the presence of impurities. Citrine quartz rock, on the other hand, is yellow due to the presence of iron impurities; chrysoprase is apple green due to the presence of nickel and hydrated salts and so on. In short, depending on the chemical structure and the contamination of other minerals, the ice-colored clear quartz can turn into many and different stones of many and beautiful quartz colors.
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A beautiful gem used mostly to make jewelry, amethyst quartz is a variety of purple quartz that takes on this hue due to the presence of iron in its crystal lattice. Its name seems to derive from the ancient Greek “Amethystos” or “not drunk”. This derives from a legend that sees as the protagonist the god of wine Bacchus who used to vent his anger on human beings when he was inebriated. One day he broke his anger on a young disciple named Amethyst by having her attacked by tigers. Artemis, goddess of the hunt, in order to defend the young woman, decided to transform her into a quartz stone statue which Dionysus then bathed with his cup of wine, transforming it into purple quartz which will later take its name from the young woman, Amethyst.
Purple quartz is the stone commonly associated with the purple color even if in nature there are many other varieties such as tanzanite and sapphire. Purple quartz color can be more or less intense depending on the composition of the crystalline habitus and the amount of iron: the more colored the stone, the greater its value. When it is brought to a temperature of over 450°C, the amethyst quartz changes color, becoming first yellow, then orange and finally brown.
Amethyst quartz crystals are bright and shiny and can have different shapes, so much so that it is possible to find it both as a single stone and in druse, that is a grouping of crystals implanted on a single portion of rock. The main quartz deposits are found all over the world and especially in Brazil, Mexico, USA, India and Bolivia; but also in northern Italy, especially in the provinces of Trento, Turin, Bolzano and Grosseto.
What is rose quartz? Undisputed symbol of femininity, love, compassion and sensitivity; rose quartz is the most used stone of all in crystal therapy treatments, a discipline of ancient Indian origins that promises to absorb the negative energy of the body and rebalance physical and mental well-being through the use of gems and crystals.
As far as the chemical composition of rose quartz is concerned, it belongs to the previously described group of macrocrystalline quartz, composed, that is, of silicon dioxide, whose crystals are visible to the naked eye. Like all quartz in this category, it is formed in pegmatitic or lava rocks and has the property of piezoelectricity. Rose quartz meaning comes from its beautiful pink color, which can vary becoming more or less intense depending on the inclusions of other minerals. When the quartz is of a more charged but opaque pink color, it means that inclusions of dumortierite, a beautiful vitreous mineral with variable colors, such as red, purple, blue and green, have occurred in rose quartz crystal lattice. When, on the other hand, rose quartz is of a very bland, almost transparent and translucent pink, it means that there have been inclusions of phosphorus and aluminum and this is the rarest variety to find and therefore much more valuable and sought after. Thanks to its brilliance capable of reflecting light and shining in the sun, of its undisputed elegance and beauty, rose quartz is used a lot as a gem to create a rose quartz necklace, rose quartz ring, rose quartz bracelet, rose quartz earrings and various jewels and according to legend, it is a gift from the god Eros to men.
Citrine quartz is a variety of crystalline quartz with calcium dioxide ranging in color from yellow to red to orange. The color of citrine quartz is due to the presence in its crystal lattice of traces, more or less intense, of iron in the trivalent form. Compared to amethyst, yellow quartz changes the oxidation state of iron and it is quite rare to find it pure in nature as most of the citrine quartz types on the market are nothing more than amethyst quartz varieties chemically treated until they reach the characteristic yellow or orange color or through a smoky quartz smoking process. Citrine quartz is found in volcanic and pegmatitic rocks, often in deep cavities and the main deposits are found in Bolivia, Brazil, USA and Madagascar. As for the price, yellow quartz is quite cheap and can range from € 10 to € 100 per carat, which can increase depending on the color, clarity and brilliance of the stone. For example, a citrine quartz without imperfections and an intense orange color can exceed € 100, but in its natural shapes and colors, it is a gem with an excellent quality-price ratio. In addition to its chemical characteristics, citrine quartz also has magical properties. In fact, according to crystal therapy, yellow quartz produces beneficial effects both on the body by stimulating the activity of the spleen, kidneys, nervous and immune systems, and on the mind, increasing self-esteem, safety, tranquility and helps to discharge the negative emotions and to combat sadness and depression.
Hyaline quartz, also called rock crystal or mountain crystal, is a variety of very pure, colorless quartz and, usually, unlike milky quartz, perfectly transparent and therefore free of inclusions. The most widespread quartz stone on earth, rock crystal has deposits that are widespread all over the world: in Russia, Canada, Germany, India and especially in Brazil. It is found inside plutonic rocks filled with hydrothermal waters rich in silicon oxide. A lava stone with a thousand magical and chemical qualities, quartz occurs in nature in both microcrystalline and macrocrystalline forms. As for the price, it varies according to purity, size, shape and cut, but all in all it does not tend to exceed € 50. Hyaline quartz can be easily found in jewelry and costume jewelry stores but also on the internet or in herbalist shops, in this case sold and marketed by virtue of its therapeutic properties on the body, mind and spirit, capable of improving meditation, relieving physical pains and balance energies, especially male ones.
Green quartz, scientifically called chrysoprase, is a variety of chalcedony that contains nickel inclusions in its crystal lattice that give it its particular apple green color. However, the color may vary depending on the impurities, ranging from mint green to light brown. Furthermore, green quartz lightens when exposed to the sun or stored in very hot places, but can easily return to its natural state if placed underground or in humid places.
Chrysoprase (green quartz) is a variety of cryptocrystalline quartz, which is composed of crystals so thin that they are impossible to see even under a microscope. On the Mohs scale, it has a hardness of 6-7, therefore slightly softer than the other varieties. Green quartz is found in deposits all over the world: in Russia, Poland, South Africa, India, USA, Germany, Madagascar and especially in Australia, specifically in central Queensland where the best specimens are found in terms of purity and size. Like all other stones, green quartz according to crystal therapy also produces numerous effects on the body and mind: it frees the psyche from obsessions by helping against addictions and fears, stimulates the correct activity of the liver and nervous system, prevents allergies and fights both female and male infertility problems.
Smoky quartz has a color that can vary from brown to gray up to black. Raw smoky quartz was born as a pure and colorless crystal but undergoes a process of natural or artificial radiation with radioactive materials such as uranium and thorium and owes its color also thanks to the inclusions of aluminum and blond rutile or copper. The color gradation of smoky quartz, from light brown to black, varies according to the duration of radiation exposure. The clearest variety of smoky quartz, dark yellow-light brown or gray-brown in color, takes the name of Cairngorm, from the name of the homonymous mountains in which it is found in abundance in Scotland. The opaque black variety of smokey quartz is called Morion or black quartz and is found mainly in France. Smoky quartz properties are, according to crystal therapy, the improvement of the survival instinct, release of stress and meditation support.
Rutilated quartz gets its name because its crystal lattice contains rutile quartz crystals, or titanium dioxide with large amounts of iron oxide in a needle-like form that can be red, gold, silver or green in its rarest forms. When the iron content is very high, the needles have a lighter color (golden rutilated quartz), while when the levels are lower, they have a very dark, almost black color (black rutilated quartz). The typical appearance of this gem is that of a hyaline or smoked quartz with thin thread-shaped inclusions generally golden.
Rutilated quartz, thanks to its beautiful streaks, is also called “Hair of Venus“, a name that derives from the Middle Ages and the belief that the stone can slow down aging. One of the most important characteristics of rutilated quartz is that it has a high refractive index compared to other minerals. It is born inside the earth, in igneous or pegmatitic rocks and on the Mohs scale it has an average hardness of 7, like all types of quartz of its variety. The deposits in which rutilated quartz are hidden are essentially found in Brazil, Madagascar, Switzerland and India. It is a much rarer variety and therefore more expensive than the other more common types. According to crystal therapy rutilated quartz also has magical and even esoteric properties: rutilated quartz is considered a very powerful psychic stone, capable of fighting eating disorders and promoting the absorption of food, but also capable of fighting depression, sadness and anxiety.
Quartz is not only a gem capable of embellishing necklaces or rings, but it is a stone with a thousand uses. Beyond purely ornamental purposes, quartz rock is also used in the technological field for the production of light bulbs, lenses, abrasives, glass, coatings and flooring. It is the raw material of the electronics industry and is used to produce all kinds of digital devices such as batteries, processors and much more. Furthermore, quartz in microgranules is used to make quartz paint, used for external surfaces thanks to its numerous properties. In short, the uses of clear quartz are truly innumerable, in addition to merely decorative and aesthetic ones.
Quartz stone is a truly versatile material and extremely elegant and refined, if wisely used. One of the most charming applications is surely that of quartz installed inside the bathroom. The best solutions are the realization of a wonderful quartz bathtub or shower (for instance the shower can be embellished by luxurious quartz shower walls). Another scenographic creation, unique in its genre, is surely the backlit quartz sink and quartz vanity tops, for an incredible relaxing and warm effect.
Kitchen manufacturers often offer a quartz countertop. Quartz countertops are tops composed of agglomerates of resins and quartz powders, available in various colors. This material surprises not only for its remarkable aesthetic impact capable of giving elegance and prestige to the kitchen, but also because it is extremely convenient in terms of resistance, versatility and durability. The great quality of using quartz for this application is also versatility and wide choice: quartz countertops colors, in fact, are numerous and this allow to adapt to every context and materials. White quartz countertops and black quartz countertops are only few of the chromatic possibilities. Quartz kitchen countertops have lots of pros. Among all, the non-porous surface of quartz doesn’t need sealing or special care; moreover, quartz countertops are incredibly durable and they suffer little from scratching or chipping. Further information about quartz countertops (also in terms of quartz vs marble) can be found in the blog.
Quartz is used in some types of quartz watches that take advantage of its piezoelectric properties. The energy of the clock battery passes through a small quartz crystal that oscillates at a frequency of 32,768 Hz and marks the time. For this reason, a quartz watch is much more accurate than a mechanical watch.
Quartz is also used to make paints to be applied to both internal and external walls. This particular type of paint is made up of water, synthetic resins and crystals quartz microgranules. The main advantages of quartz paint are that it is very simple to apply and spread, prevents the formation of algae and mold, is resistant to UV rays and abrasion and is very easy to find.
As for prices, a 14-liter can start from € 20 upwards, but on the market, they are also available in a cheaper version in the form of acrylic quartz paint, but also more expensive, from € 100 upwards for the more particular ones.
Quartz sand is widely used in the construction field. It is a sand composed of crushed, dried and sieved quartz rock and other elements such as carbonates, iron oxides, feldspar and clayey matter. From yellow to dark red in color, quartz sands contain up to 99% silica. Its use in the construction field is very varied: it is used for the purification of drinking water, for sandblasting and abrasives, for flooring and wall coverings, for sanitary ware and much more.