Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Rhyolite is a fine-grained igneous rock which is rich in silica
From German Rhyolit, from Greek rhuax lava stream + lithos stone
Coarse Grained Rock, Opaque Rock
Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture
From Tonale Pass, northern Italy, + -ite1
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock