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Quartzite. Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone. [1][2] Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and ...
Orthoclase, or orthoclase feldspar (endmember formula K Al Si 3 O 8), is an important tectosilicate mineral which forms igneous rock. The name is from the Ancient Greek for "straight fracture", because its two cleavage planes are at right angles to each other. It is a type of potassium feldspar, also known as K-feldspar.
Orthorhombic crystal system. In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (a by b) and height (c), such that a, b, and c are ...
Garnet bearing amphibolite from Val di Fleres, Italy. Amphibolite (/ æmˈfɪbəlaɪt /) is a metamorphic rock that contains amphibole, especially hornblende and actinolite, as well as plagioclase feldspar, but with little or no quartz. It is typically dark-colored and dense, with a weakly foliated or schistose (flaky) structure.
Metamorphic rock. Quartzite, a type of metamorphic rock. Metamorphic rock, deformed during the Variscan orogeny, at Vall de Cardós, Lérida, Spain. Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than 150 ...
In the hexagonal family, the crystal is conventionally described by a right rhombic prism unit cell with two equal axes (a by a), an included angle of 120° (γ) and a height (c, which can be different from a) perpendicular to the two base axes. The hexagonal unit cell for the rhombohedral Bravais lattice is the R-centered cell, consisting of ...
A ganister (or sometimes gannister[1] ) is hard, fine-grained quartzose sandstone, or orthoquartzite, [2] used in the manufacture of silica brick typically used to line furnaces. Ganisters are cemented with secondary silica and typically have a characteristic splintery fracture. Cornish miners originally coined this term for hard, chemically ...
Sioux Quartzite at Falls Park, Sioux Falls, South Dakota Cross-bedding in the Sioux Quartzite, Blue Mounds State Park, Minnesota, United States.. The Sioux Quartzite is a Proterozoic quartzite that is found in the region around the intersection of Minnesota, South Dakota, and Iowa, and correlates with other rock units throughout the upper midwestern and southwestern United States.