Porphyries

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Porphyry \Por"phy*ry\, n.; pl. {Porphyries}. [F. porphyre, L.
     porphyrites, fr. Gr. ? like purple, fr. ? purple. See
     {Purple}.] (Geol.)
     A term used somewhat loosely to designate a rock consisting
     of a fine-grained base (usually feldspathic) through which
     crystals, as of feldspar or quartz, are disseminated. There


     are red, purple, and green varieties, which are highly
     esteemed as marbles.
     [1913 Webster]
  
     {Porphyry shell} (Zool.), a handsome marine gastropod shell
        ({Oliva porphyria}), having a dark red or brown polished
        surface, marked with light spots, like porphyry.
        [1913 Webster]