glassy feldspar

2 definitions found

glassy feldspar - Collaborative International Dictionary of English v.0.48 :

  Glassy \Glass"y\, a.
     1. Made of glass; vitreous; as, a glassy substance. --Bacon.
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     2. Resembling glass in its properties, as in smoothness,
        brittleness, or transparency; as, a glassy stream; a
        glassy surface; the glassy deep.
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     3. Dull; wanting life or fire; lackluster; -- said of the
        eyes. "In his glassy eye." --Byron.
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     Glassy feldspar (Min.), a variety of orthoclase; sanidine.
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  Sanidine \San"i*dine\, n. [Gr. ?. ?, a board. So called in
     allusion to the tabular crystals.] (Min.)
     A variety of orthoclase feldspar common in certain eruptive
     rocks, as trachyte; -- called also glassy feldspar.
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