Definition
Origin
Discoverer
Etymology
Class
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Other Categories
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Fine Grained Rock, Opaque Rock
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock