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Some solid substances that are not minerals have been assigned a hardness on the Mohs scale. Hardness may be difficult to determine, or may be misleading or meaningless, if a material is a mixture of two or more substances; for example, some sources have assigned a Mohs hardness of 6 or 7 to granite but it is a rock made of several minerals ...
Dolomite (/ ˈ d ɒ l. ə ˌ m aɪ t, ˈ d oʊ. l ə-/) is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally CaMg(CO 3) 2. The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite (see Dolomite (rock) ).
Dolomite outcrops are recognized in the field by their softness (mineral dolomite has a Mohs hardness of 4 or less, well below common silicate minerals) and because dolomite bubbles feebly when a drop of dilute hydrochloric acid is dropped on it. This distinguishes dolomite from limestone, which is also soft but reacts vigorously with dilute ...
Mohs scale of mineral hardness; Mohs hardness of materials (data page) Vickers hardness test; Brinell scale This page was last edited on ...
Many are intergrown with other minerals, such as calcite and dolomite. The basic structural unit of serpentine is a polar layer 0.72 nm thick. A Mg -rich trioctahedral sheet is tightly linked on one side to a single tetrahedral silicate sheet , regardless of the 3–5% larger lateral lattice dimensions of the octahedral sheet . [ 10 ]
Mohs scale hardness: 6.5–7: ... they are not true agates according to the mineralogical definition. [1] ... but instead formed within the limestone and dolomite ...
Mohs's scale had two limitations: it was not linear, and most modern abrasives fall between 9 and 10.; [6] [7] so, later scientists attempted to increase resolution at the harder end of the scale. Raymond R. Ridgway, a research engineer at the Norton Company, modified the Mohs scale by giving garnet a hardness of 10 and diamond a hardness of 15.
Tremolite forms by metamorphism of sediments rich in dolomite and quartz, and occurs in two distinct forms, crystals and fibers. Tremolite forms a series with actinolite and ferro-actinolite. Pure magnesium tremolite is creamy white, but the color grades to dark green with increasing iron content. It has a hardness on Mohs scale of 5 to 6.