trondhjemite

[tron-ye-mahyt]

noun Petrology.

a coarse-grained igneous rock composed of quartz, plagioclase feldspar, and a small amount of biotite.

Origin of trondhjemite

Trondhjem (now Trondheim) + -ite¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018