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