Ophitic

adjective Etymology: ophite serpentine (stone), from Latin ophites, from Greek ophitēs (lithos), from ophitēs snakelike, from ophis snake; akin to Sanskrit ahi snake and probably to Latin anguis snake, anguilla eel, Greek enchelys eel, echidna viper, echinos hedgehog, Old English igil having or being a rock fabric in which lath-shaped plagioclase crystals are enclosed in later formed augite

Merriam-Webster's Collegiate Dictionary