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Amethyst is a violet variety of quartz.The name comes from the Koine Greek αμέθυστος amethystos from α - a-, "not" and μεθύσκω (Ancient Greek) methysko / μεθώ metho (Modern Greek), "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. [1]
The subscript "n" denotes the degree of polymerisation, that is, the number of units linked together. The molecular mass of the repeat unit, M R, is simply the sum of the atomic masses of the atoms within the repeat unit. The molecular mass of the chain is just the product nM R.
Cartesian y-axis basis unit vector unitless kinetic energy: joule (J) wave vector: radian per meter (m −1) Boltzmann constant: joule per kelvin (J/K) wavenumber: radian per meter (m −1) stiffness: newton per meter (N⋅m −1) ^ Cartesian z-axis basis unit vector
Celadonite is a mica group mineral, a phyllosilicate of potassium, iron in both oxidation states, aluminium and hydroxide with formula K(Mg,Fe 2+)(Fe 3+,Al)[Si 4 O 10](OH) 2.. It crystallizes in the monoclinic system and usually forms massive aggregates of prismatic crystallites or, more commonly, in dull clay masses.
Greek letters are used in mathematics, science, engineering, and other areas where mathematical notation is used as symbols for constants, special functions, and also conventionally for variables representing certain quantities. In these contexts, the capital letters and the small letters represent distinct and unrelated entities.
The Miscellaneous Mathematical Symbols-B block (U+2980–U+29FF) contains miscellaneous mathematical symbols, including brackets, angles, and circle symbols. Miscellaneous Mathematical Symbols-B [1] Official Unicode Consortium code chart (PDF)
Rhodonite is a manganese inosilicate, with the formula (Mn, Fe, Mg, Ca)SiO 3, and member of the pyroxenoid group of minerals, crystallizing in the triclinic system. It commonly occurs as cleavable to compact masses with a rose-red color (its name comes from Ancient Greek ῥόδον (rhódon) 'rose'), often tending to brown due to surface oxidation.
Although the unit cell is close to being hexagonal in shape ("a" and "c" are nearly equal and β nearly 120°), it is inherently monoclinic and cannot be hexagonal. The crystal structure of coesite is similar to that of feldspar and consists of four silicon dioxide tetrahedra arranged in Si 4 O 8 and Si 8 O 16 rings.