Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
From German Grauwacke, from grau grey + wacke
Fine Grained Rock, Opaque Rock
Harzburgite is a plutonic rock of the peridotite group consisting largely of orthopyroxene and olivine
From the name of a town in Harzburg, Germany
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Opaque Rock