Definition
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
USA
-
Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
From 17th century, because of its greasy feel and use like a soap
From Greek trakhus rough’ or trakhutēs roughness
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock