porphyroid


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por·phy·roid

 (pôr′fə-roid′)
n.
Metamorphic rock having porphyritic texture.

porphyroid

(ˈpɔːfɪˌrɔɪd)
adj
(Geological Science) (of metamorphic rocks) having a texture characterized by large crystals set in a finer groundmass
n
(Geological Science) a metamorphic rock having this texture
References in periodicals archive ?
The relict porphyroid texture of the rock is caused by the presence of olivine coarse grains (separated by a fine grained mass composed of serpentine grains and ore mineral) fully substituted by serpentine.
They locally contain intercalations of crystalline limestones and dolomites (marbles), amphibolites, amphibole schists, quartzite and quartzite schists, graphite quartzites and mica schists, porphyroids and leptynites.
Fine flakes of muscovite (sericite) and chlorite are typical constituents of shales, slates, phyllites, porphyroids, etc.