Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Wehrlite is an ultramafic and ultrabasic rock that is a mixture of olivine and clinopyroxene. It is a subdivision of the peridotites
History
Origin
-
Egypt
Discoverer
Unknown
Alois Wehrle
Etymology
From German Grauwacke, from grau grey + wacke
From the name of a professor, Alois Wehrle
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock