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Durr Al Najaf (Arabic: دُر ٱلنَّجَف) is a glossy and clear gemstone from the quartz family. The name means "pearl of Najaf" as it can only be sourced from Wadi-al-Salaam (Arabic: وادي السلام, romanized: Wādī al-Salām, lit. 'Valley of Peace') in Najaf, Iraq. The gemstone is found along the west of Najaf close by the Najaf ...
Rutilated quartz is a variety of quartz which contains acicular (needle-like) inclusions of rutile. [1] It is used for gemstones. These inclusions mostly look golden, but they also can appear silver, copper red or black.
Acicular, in mineralogy, refers to a crystal habit composed of slender, needle-like crystals. Crystals with this habit tend to be fragile. Complete, undamaged acicular specimens are uncommon. Needle-shaped acicular millerite crystals on white quartz. The term "acicular" derives from the Late Latin "acicula" meaning "little needle". [1]
The UV absorption of nano-sized rutile particles is blue-shifted compared to bulk rutile so that higher-energy UV light is absorbed by the nanoparticles. Hence, they are used in sunscreens to protect against UV-induced skin damage. Small rutile needles present in gems are responsible for an optical phenomenon known as asterism. Asteriated gems ...
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 ...
Ceramic Raschig rings.....and plastic Białecki rings of increased SSA. Values obtained for specific surface area depend on the method of measurement. In adsorption based methods, the size of the adsorbate molecule (the probe molecule), the exposed crystallographic planes at the surface and measurement temperature all affect the obtained specific surface area. [4]
The Spruce Pine Mining District is a swath of the valley of the North Toe River in the Blue Ridge Mountains of northwestern North Carolina. The area is mined for its mica, kaolin, quartz and feldspar. [1] Spruce Pine district is one of the largest suppliers of high-purity quartz, which is used in the manufacture of silicon for integrated ...
Granite (/ ˈ ɡ r æ n ɪ t / GRAN-it) is a coarse-grained intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase.It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground.