Dictionary.com

phenocryst

[ fee-nuh-krist, fen-uh- ]
/ ˈfi nə krɪst, ˈfɛn ə- /
Save This Word!

noun Petrology.
any of the conspicuous crystals in a porphyritic rock.
QUIZ
ARE YOU A TRUE BLUE CHAMPION OF THESE "BLUE" SYNONYMS?
We could talk until we're blue in the face about this quiz on words for the color "blue," but we think you should take the quiz and find out if you're a whiz at these colorful terms.
Question 1 of 8
Which of the following words describes “sky blue”?
Meet Grammar CoachWrite or paste your essay, email, or story into Grammar Coach and get grammar helpImprove Your Writing
Meet Grammar CoachImprove Your Writing
Write or paste your essay, email, or story into Grammar Coach and get grammar help

Origin of phenocryst

First recorded in 1890–95; pheno- + cryst(al)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for phenocryst

phenocryst
/ (ˈfiːnəˌkrɪst, ˈfɛn-) /

noun
any of several large crystals that are embedded in a mass of smaller crystals in igneous rocks such as porphyry

Word Origin for phenocryst

C19: from pheno- (shining) + crystal
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

Scientific definitions for phenocryst

phenocryst
[ fēnə-krĭst′ ]

A large crystal that is surrounded by a finer-grained matrix in an igneous rock. Phenocrysts are usually the first crystals to form from a cooling magma, and therefore have sufficient room to grow to a large size. They are analogous to porphyroblasts in metamorphic rock.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK