Definition
Origin
Discoverer
Etymology
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Other Categories
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock
Vogesite is a porphyritic alkaline igneous rock and is a variety of Lamprophyre which is dominated by essential amphibole, usually hornblende, and potassic feldspar
From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock