Ophitic

Part of speech: adjective

Definitions

1. A texture in igneous rocks where elongated minerals are partially or completely enclosed by larger crystals, typically plagioclase surrounded by pyroxene
2. A type of rock texture found in igneous formations where elongated crystals are surrounded by larger ones, often involving plagioclase enveloped by pyroxene minerals
3. This term describes a mineralogical arrangement in igneous rocks where long, slender crystals are encased within larger crystal structures, frequently involving combinations of plagioclase and pyroxene

Etymology: "Ophitic" is built from "ophite" plus the adjective suffix "-ic". The base word "ophite" names a rock, and the root behind it is the Greek "ophis", meaning "serpent" or "snake". The stone was named for its mottled, snake-skin appearance, a surface pattern that the greenish, speckled rock shows when polished. The adjective gives geologists a precise way to describe a texture rather than a rock type. In an ophitic texture, slender crystals of plagioclase feldspar lie scattered within larger grains of pyroxene, so the pyroxene appears to enclose the feldspar. The term is applied mainly to igneous rocks such as dolerite and basalt, where this arrangement records how the minerals crystallised as magma cooled.