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