Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Travertine is a mineral consisting of layered calcium carbonate formed by deposition from spring waters
From Italian travertino a kind of building stone, from Tiburs, adjective from Tibur (Tivoli), in Italy
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
From French, Latin lignum wood + -ite1
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock