Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
Brazil
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Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
from French néphéline, from Greek nephelē
From Greek trakhus rough’ or trakhutēs roughness
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock