Definition
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
Trachyandesite is an extrusive igneous rock.
History
Origin
USA
Indonesia
Discoverer
Unknown
Unknown
Etymology
From 17th century, because of its greasy feel and use like a soap
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
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