Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
History
Origin
-
Adak, Aleutian Islands
Discoverer
Alexandre Brongniart and René Just Haüy
Defant and Drummond
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From Adak, Aleutian Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock