Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
History
Origin
Hawaii Islands
Brazil
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
from French néphéline, from Greek nephelē
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
Fine Grained Rock, Opaque Rock