Definition
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
France
-
Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
From Latin varius, speckled, variegated
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
Opaque Rock
Fine Grained Rock, Opaque Rock