Definition
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Etymology
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Other Categories
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
Coarse 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