Definition
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture
History
Origin
Germany
Tonale, Italy
Discoverer
Christian Leopold von Buch
Warren Hamilton
Etymology
From Latin glaber bare, smooth, bald
From Tonale Pass, northern Italy, + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Plutonic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock