Definition
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
History
Origin
-
North America
Discoverer
Unknown
Theodor von Gümbel
Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
From Andes mountains, where it is found in abundance
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock