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Care and maintenance. Care and maintenance is a term used in the mining industry to describe processes and conditions on a closed mine site at which there is the potential to recommence operations at a later date. During the care and maintenance phase, production is stopped but the site is managed to ensure it remains in a safe and stable ...
QFL diagram. Ternary diagram showing the relative abundance of quartz, feldspar, and lithic grains and views of what selected compositions would look like. A QFL diagram or QFL triangle is a type of ternary diagram that shows compositional data from sandstones and modern sands, point counted using the Gazzi-Dickinson method.
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2. Quartz is, therefore, classified structurally as a framework silicate mineral and ...
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). [1]
Diorite. Diorite (/ ˈdaɪ.əraɪt / DY-ə-ryte) [1][2] is an intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is intermediate in composition between low-silica (mafic) gabbro and high-silica (felsic) granite.
A QAPF diagram is a doubled-triangle plot diagram used to classify intrusive igneous rocks based on their mineralogy. The acronym QAPF stands for " Quartz, Alkali feldspar, Plagioclase, Feldspathoid (Foid) ", which are the four mineral groups used for classification in a QAPF diagram. The percentages (ratios) of the Q, A, P and F groups are ...
Prasiolite. Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, [citation needed] but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay ...
The room-temperature form of quartz, α-quartz, undergoes a reversible change in crystal structure at 573 °C to form β-quartz. This phenomenon is called an inversion, and for the α to β quartz inversion is accompanied by a linear expansion of 0.45%. This inversion can lead to cracking of ceramic ware if cooling occurs too quickly through ...