Serpentinized

Part of speech: adjective, verb

Definitions

1. Describing rock transformed through a geological process by hydration and metamorphism involving ultramafic minerals converting into serpentine group minerals
2. Referring to a geological alteration whereby original minerals in rock chemically change due to water interaction, producing a characteristic greenish serpentine mineral texture
3. Characteristic of rocks that have undergone a mineralogical transformation resulting in the formation of serpentine minerals through the interaction of water with mantle-derived ultramafic rocks

Etymology: Serpentinite is named for serpentine, a mineral whose greenish, mottled surface was compared to snake skin, and the Latin "serpentinus" meant "of a serpent." The mineral name passed into English through Old French and Medieval Latin, but the verb "serpentinize" and its adjective are much newer, built in English by geologists from the noun. The process they describe, in which water reacts with olivine and pyroxene in ultramafic rock and turns it into serpentine minerals, is what gives the rock its characteristic texture. The change adds water to the rock's crystal structure, so the original minerals are not simply weathered away but rebuilt into a different mineral family. Because the reaction also releases heat and alters the rock's volume, serpentinized zones can be sites of notable geological activity, which is why the term appears in discussions of oceanic crust and fault zones.

Synonyms: serpentinized