Definition
Origin
Discoverer
Etymology
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Other Categories
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Western Australia, Minnesota
From its formation process
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Opaque Rock