Definition
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Etymology
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Other Categories
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
Larvikite is an igneous rock and a variety of monzonite, notable for the presence of thumbnail-sized crystals of feldspar
From the town of Larvik in Norway, where this type of igneous rock is found
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock