porphyroid

[ pawr-fuh-roid ]

noun
  1. a rock resembling porphyry.

  2. a sedimentary rock that has been metamorphosed so as to leave some original crystals in a fine-textured, layered matrix.

Origin of porphyroid

1
First recorded in 1790–1800; porphyr(y) + -oid

Words Nearby porphyroid

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How to use porphyroid in a sentence

  • Pumice and trachyte are the most common rocks around this mountain, and these are augitic or porphyroid.

British Dictionary definitions for porphyroid

porphyroid

/ (ˈpɔːfɪˌrɔɪd) /


adjective
  1. (of metamorphic rocks) having a texture characterized by large crystals set in a finer groundmass

noun
  1. a metamorphic rock having this texture

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012