Petrology at the California Institute

Abstract

To the layman, "petrology" is a word with an obviously petroliferous connotation; but to many a geologist any connection between this word and an oil pool is little more than coincidental. Have the Greeks, then, led us astray? Not so. The Greek word petra, meaning "stone" or "rock," appears as a root in many well-known English words. Thus we have petrify, meaning to "turn into stone," and petroleum, meaning "the oil that comes from rock." Similarly petrology means "the science of rocks." Unfortunately, relatively few rocks contain oil; hence the observation above that most petrologists are not necessarily oil experts.