Main Entry: tho·lei·ite

Pronunciation: \ˈtō-lə-ˌīt, ˈthō-\

Function: noun

Etymology: German Tholeiit, from Tholey, village in Saarland, Germany + German -it -ite

Date: 1866

: a basaltic rock that is rich in aluminum and low in potassium, is found typically in the ocean floor, and is probably derived from the earth's mantle

— tho·lei·it·ic \ˌtō-lə-ˈi-tik, ˌthō-\ adjective