A microscopic skeletal plate made of calcite that protects certain Marine phytoplankton and which, in a fossilized state, forms chalk and limestone deposits.
由方解石制成的显微骨架板，保护某些海洋浮游植物，而且它在变成化石状态时形成白垩和石灰石沉积物。
Any of various colonial Marine hydrozoans of the order Hydrocorallinae, having a limestone skeleton and thus resembling the true corals.
属于水生珊瑚虫类的多种集群海生水螅虫的任何一种，其有石灰石结构，类似真正的珊瑚。
In its compounds calcium has valence 2. It occurs in limestone, chalk, marble, dolomite, eggshells, pearls, coral, and many marine shells as calcium carbonate, or calcite;
钙以方解石（碳酸钙）的形式存在于石灰岩、白垩、大理石、白云石、蛋壳、珍珠、珊瑚、钟乳石、石笋和许多海洋动物的壳体中。
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