Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Charnockite is a variety of granite containing minerals like orthopyroxene, quartz, and feldspar
History
Origin
-
Tamil Nadu, India
Discoverer
Unknown
T. H. Holland
Etymology
From German Grauwacke, from grau grey + wacke
From Job Charnock, an administtrator of East India Company
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
-
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock