Definition
Shoshonite is a basaltic rock, properly a potassic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
History
Origin
Wyoming,USA
-
Discoverer
Iddings
Unknown
Etymology
From the place of origin called Shoshone riverin Wyoming
From English feldspar and -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock