Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Claystone is a fine-grained, dark gray to pink sedimentary rock which mainly consists of compacted and hardened clay
History
Origin
Egypt
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Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From English clay and stone as the rock contains more amount of clay
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
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Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock