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Our Products |
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What Is A Quartz ? |
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Quartz is the most common mineral found on the surface of the Earth. A significant component of many igneous, metamorphic and sedimentary rocks, this natural form of silicon dioxide is found in an impressive range of varieties and colours. 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. |
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Typical Properties of Cenospheres |
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Crystal habit
Quartz belongs to the rhombohedral 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, but because the crystals must be attached at the other end to a matrix, only one termination pyramid is present. |
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A quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward. |
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Varieties: |
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Pure quartz, sometimes called clear quartz, is colorless or white and transparent (clear) or translucent. 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 |
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Physical Properties of Quartz |
LUSTRE: |
Vitreous |
DIAPHANEITY (TRANSPARENCY): |
Transparent, Translucent |
COLOUR: |
Colorless, Black etc. |
STREAK: |
White |
HARDNESS (MOHS): |
7 |
HARDNESS DATA: |
Mohs hardness reference species |
TENACITY: |
Brittle |
CLEAVAGE: |
Poor/Indistinct |
FRACTURE: |
Conchoidal |
COMMENT: |
Tough when massive |
DENSITY (MEASURED): |
2.65 - 2.66 g/cm3 |
DENSITY (CALCULATED): |
2.66 g/cm3 |
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