Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
History
Origin
Hawaii Islands
Romania and Moldova, Europe
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock