Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
History
Origin
Egypt
Germany
Discoverer
Unknown
Christian Leopold von Buch
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Greek di + base
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock