Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
History
Origin
Brazil
USA
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock