Definition
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Discoverer
Etymology
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Other Categories
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
From French schiste, Greek skhistos i.e. split
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
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