Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Travertine is a mineral consisting of layered calcium carbonate formed by deposition from spring waters
History
Origin
Brazil
Italy
Discoverer
Unknown
Marcus Vitruvius Pollio
Etymology
from French néphéline, from Greek nephelē
From Italian travertino a kind of building stone, from Tiburs, adjective from Tibur (Tivoli), in Italy
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock