Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Trachyandesite is an extrusive igneous rock.
History
Origin
-
Indonesia
Discoverer
Unknown
Unknown
Etymology
From German Grauwacke, from grau grey + wacke
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock