| apophyllite | <chemical> A mineral relating to the zeolites, usually occurring in square prisms or octahedrons with pearly luster on the cleavage surface. It is a hydrous silicate of calcium and potassium. Origin: Pref. Apo- + Gr. Leaf; so called from its foliated structure or easy cleavage. Source: Websters Dictionary (01 Mar 1998) |
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