phenocrystic


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phe·no·cryst

 (fē′nə-krĭst′)
n.
A conspicuous, usually large, crystal embedded in porphyritic igneous rock.


phe′no·crys′tic adj.

phenocrystic

(ˌfiːnəˈkrɪstɪk)
adj
(Geological Science) relating to a phenocryst
References in periodicals archive ?
The andesite has a maximum thickness of 85 m, and it is a non-vesicular, phenocrystic andesite with veins and vugs.
These are phenocrystic rhyolites (or quartz porphyries) recovered from a drill core on the Undva Peninsula, western Saaremaa, underlain by plagioclase porphyrites (Niin 1976).
Phenocrystic plagioclase forms euhedral to subhedral tabular crystals, ranging from 1 to 12 mm long, with rectangular cross sections and polysynthetic albite twinning.