Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
History
Origin
-
Western Australia, Minnesota
Discoverer
Alexandre Brongniart and René Just Haüy
Johann Gottlob Lehmann
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From its formation process
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock