Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
History
Origin
Egypt
Hawaii Islands
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Greek pikros bitter + -ite, 19th century
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, Opaque Rock