Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
History
Origin
Hawaii Islands
England
Discoverer
Unknown
Abraham Gottlob Werner
Etymology
From Greek pikros bitter + -ite, 19th century
From Old French esclate, from esclat (French éclat)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock