Definition
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
Rhyolite is a fine-grained igneous rock which is rich in silica
History
Origin
Germany
North America
Discoverer
Christian Leopold von Buch
Ferdinand von Richthofen
Etymology
From Latin glaber bare, smooth, bald
From German Rhyolit, from Greek rhuax lava stream + lithos stone
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock