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
Syenite is a coarse-grained igneous rock which is composed mainly of alkali feldspar and various ferromagnesian minerals
History
Origin
Wyoming,USA
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Discoverer
Iddings
Unknown
Etymology
From the place of origin called Shoshone riverin Wyoming
From French syénite, from Latin Syenites (lapis ) (stone) of Syene
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Plutonic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock