Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
History
Origin
-
North America
Discoverer
Alexandre Brongniart and René Just Haüy
Theodor von Gümbel
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From Andes mountains, where it is found in abundance
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
Fine Grained Rock, Opaque Rock