Definition
Origin
Discoverer
Etymology
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Other Categories
Greenschist is a metamorphic rock that is formed under lowest temperatures and pressures and is usually produced by regional metamorphism
From minerals such as chlorite, serpentine, and epidote, and platy minerals such as muscovite and platy serpentine which are green in color
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Fine Grained Rock, Opaque Rock