Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
History
Origin
Hawaii Islands
USA
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock