Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Vogesite is a porphyritic alkaline igneous rock and is a variety of Lamprophyre which is dominated by essential amphibole, usually hornblende, and potassic feldspar
History
Origin
-
-
Discoverer
Alexandre Brongniart and René Just Haüy
Unknown
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock