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