Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
History
Origin
-
Indonesia
Discoverer
Unknown
Cornish Gossen
Etymology
From German Grauwacke, from grau grey + wacke
From Cornish gossen from gos, blood from Old Cornish guit
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock