Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture
History
Origin
Hawaii Islands
Tonale, Italy
Discoverer
Unknown
Warren Hamilton
Etymology
From Greek pikros bitter + -ite, 19th century
From Tonale Pass, northern Italy, + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock