Definition
Origin
Discoverer
Etymology
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Other Categories
Flint is a hard type of sedimentary rock that produces a small piece of burning material when hit by steel
From Old English flint - a type of rock mainly known for high hardness and for giving off sparks when struck
Fine Grained Rock, Opaque Rock
Ijolite is an intrusive igneous rock which is composed mainly of nepheline and an alkali pyroxene, usually aegirine-augite
From the first syllable of the Finnish words Ii-vaara, Iijoki, &c. commonly used geographical names in Finland, and the Gr. Xiflos, a stone
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Opaque Rock