Definition
Origin
Discoverer
Etymology
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Other Categories
Appinite is an igneous rock in which the crystals are so fine grained that individual minerals cannot be easily distinguished
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
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock