• Chambers's Twentieth Century Dictionary
    • n Porphyroid a crystalline and schistose rock containing porphyritic crystals of feldspar
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Chambers's Twentieth Century Dictionary
Through Fr. and L. from Gr. porphyritesporphyra, purple.


In literature:

Some of the porphyroids are conglomerate, but the majority are true porphyries, having a homogeneous base.
"The Andes and the Amazon" by James Orton
The most prominent member of the Cango series is a coarse conglomerate; the other rocks include slates, limestone and porphyroids.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 2" by Various