Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
History
Origin
Hawaii Islands
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Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
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Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock