Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
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
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Fine Grained Rock, Opaque Rock