Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Oolite is a sedimentary rock formed from ooids, spherical grains which are composed of concentric layers of calcite
History
Origin
Egypt
-
Discoverer
Unknown
William Smith
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From oo- + -lite, after German Oolit. A rock consisting of fine grains of carbonate of lime
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock