“aragonite”的概念、定义、翻译、参考文献-科学参考

aragonite

Chemistry

A rock-forming anhydrous mineral form of calcium carbonate, CaCO₃. It is much less stable than calcite, the commoner form of calcium carbonate, from which it may be distinguished by its greater hardness and specific gravity. Over time aragonite undergoes recrystallization to calcite. Aragonite occurs in cavities in limestone, as a deposit in limestone caverns, as a precipitate around hot springs and geysers, and in high-pressure low-temperature metamorphic rocks; it is also found in the shells of a number of molluscs and corals and is the main constituent of pearls. It is white or colourless when pure but the presence of impurities may tint it grey, blue, green, or pink.

Geology and Earth Sciences

Mineral, CaCO₃; sp. gr. 2.9; hardness 3.5–4.0; orthorhombic; colourless, white, grey, or yellowish; white streak; vitreous lustre; crystals normally prismatic, often acicular, sometimes tabular and pseudo-hexagonal; also occurs fibrous and stalactitic; cleavage imperfect {010}; occurs in hot springs and in association with gypsum, also in veins and cavities, and in the oxidized zone of ore deposits with other secondary minerals. Aragonite is a polymorph of calcite, from which it is distinguished by its lack of cleavage and its higher specific gravity. Calcite is the more stable form of CaCO₃, and many fossil shells that were made originally of aragonite have either converted to calcite or undergone replacement by some other mineral. Present-day mollusc shells are formed of aragonite crystals. The name is derived from the Aragon province of Spain. See also carbonates.

单词	aragonite
释义	aragonite Chemistry A rock-forming anhydrous mineral form of calcium carbonate, CaCO₃. It is much less stable than calcite, the commoner form of calcium carbonate, from which it may be distinguished by its greater hardness and specific gravity. Over time aragonite undergoes recrystallization to calcite. Aragonite occurs in cavities in limestone, as a deposit in limestone caverns, as a precipitate around hot springs and geysers, and in high-pressure low-temperature metamorphic rocks; it is also found in the shells of a number of molluscs and corals and is the main constituent of pearls. It is white or colourless when pure but the presence of impurities may tint it grey, blue, green, or pink. Geology and Earth Sciences Mineral, CaCO₃; sp. gr. 2.9; hardness 3.5–4.0; orthorhombic; colourless, white, grey, or yellowish; white streak; vitreous lustre; crystals normally prismatic, often acicular, sometimes tabular and pseudo-hexagonal; also occurs fibrous and stalactitic; cleavage imperfect {010}; occurs in hot springs and in association with gypsum, also in veins and cavities, and in the oxidized zone of ore deposits with other secondary minerals. Aragonite is a polymorph of calcite, from which it is distinguished by its lack of cleavage and its higher specific gravity. Calcite is the more stable form of CaCO₃, and many fossil shells that were made originally of aragonite have either converted to calcite or undergone replacement by some other mineral. Present-day mollusc shells are formed of aragonite crystals. The name is derived from the Aragon province of Spain. See also carbonates.
随便看	brainstem brain transplants Braithwaite, Richard Bevan (1900–90) brake horsepower bramble branch branch and bound branch and bound algorithm branch and bound method(of solving the knapsack problem) branch banking branched chain branchial branchial arch branchial basket branching decay branching factor branching process branching quantifier branch instruction Branchiopoda branch(of a hyperbola) branch point branch point(complex analysis) branch testing brand