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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. [9] Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation ...
The basic level of definition is that of mineral species, each of which is distinguished from the others by unique chemical and physical properties. For example, quartz is defined by its formula, SiO 2, and a specific crystalline structure that distinguishes it from other minerals with the same chemical formula (termed polymorphs). When there ...
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as ...
Quartz framework grains are the dominant minerals in most clastic sedimentary rocks; this is because they have exceptional physical properties, such as hardness and chemical stability. [1] These physical properties allow the quartz grains to survive multiple recycling events, while also allowing the grains to display some degree of rounding. [1]
This property is used to grow single crystals of quartz in a hydrothermal process where natural quartz is dissolved in superheated water in a pressure vessel that is cooler at the top. Crystals of 0.5–1 kg can be grown for 1–2 months. [12] These crystals are a source of very pure quartz for use in electronic applications. [15]
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, [1] [2] categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start fires. Flint occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones.
Among the physical processes, the differential thermal expansion of individual mineral grains, the anisotropic expansion of certain minerals, and polymorphic transformations, such as the alpha-beta quartz transition, induce substantial volume changes and generate internal stresses that damage the granite.
For quartz mining, pegmatites with central quartz masses have been of particular interest. [26] Pegmatites are the primary source of lithium either as spodumene, lithiophyllite or usually from lepidolite. [27] The primary source for caesium is pollucite, a mineral from a zoned pegmatite. [28]