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The Borate Minerals are minerals which contain a borate anion group. The borate (BO 3) units may be polymerised similar to the SiO 4 unit of the silicate mineral class. This results in B 2 O 5, B 3 O 6, B 2 O 4 anions as well as more complex structures which include hydroxide or halogen anions. [2] The [B(O,OH) 4] − anion exists as well.
Borates are formed when boron bearing solutions, caused from the leaching of pyroclastic rocks, flow into isolated basins where evaporation then takes place. Over time, borates deposit and form into stratified layers. Ulexite occurs in salt playas and dry saline lakes in association with large-scale gypsum deposits and Na-Ca borates. [8]
Cumulate rock – Igneous rocks formed by the accumulation of crystals from a magma either by settling or floating. Flow banding – Bands or layers that can sometimes be seen in rock that formed from magma; Fractional crystallization (chemistry) – Method for refining substances based on differences in their solubility
Borate ions occur, alone or with other anions, in many borate and borosilicate minerals such as borax, boracite, ulexite (boronatrocalcite) and colemanite. Borates also occur in seawater, where they make an important contribution to the absorption of low frequency sound in seawater. [1] Borates also occur in plants, including almost all fruits. [2]
A rock formation is an isolated, scenic, or spectacular surface rock outcrop. Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term rock formation can also refer to specific sedimentary strata or other rock unit in stratigraphic and petrologic studies.
An important synthetic application using such dialkylboranes, such as diethylborane, is the transmetallation of the organoboron compounds to form organozinc compounds. [9] [10] Some diaryl and dialkylboranes are well known. Dimesitylborane is a dimer (C 6 H 2 Me 3) 4 B 2 H 2). It reacts only slowly with simple terminal alkenes.
Most of the white varieties of turquoise are chalk-like with a Mohs hardness of 1, and are not as hard or durable as howlite, and subsequently require stabilization in order to be used in jewelry, which has resulted in howlite being more popular for use in jewelry than the artificially stabilized white forms of the mineral turquoise. [9]
Metamorphic rocks once existed as igneous or sedimentary rocks, but have been subjected to varying degrees of pressure and heat within the Earth's crust. The processes involved will change the composition and fabric of the rock and their original nature is often hard to distinguish. Metamorphic rocks are typically found in areas of mountain ...