Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
History
Origin
France
USA
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock