Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
History
Origin
-
Italy
Discoverer
Alexandre Brongniart and René Just Haüy
Unknown
Etymology
From Greek trakhus rough’ or trakhutēs roughness
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock