a granualr, plutonic igneous rock, a variety a diorite, containing quartz, plagioclase, and biotite or hornblende. [AHDOS
Tonalite is an igneous, plutonic (intrusive) rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically oligoclase or andesine) with 10% or less alkali feldspar. Quartz is present as more than 20% of the rock.