porphyroid
/ˈpɔːfɪrɔɪd/Geology
noun
A rock having a porphyritic texture, especially one which is metamorphic in origin.
adjective
Porphyritic.
Origin
Late 18th century; earliest use found in Richard Kirwan (1733–1812), chemist and mineralogist. From porphyr- + -oid.