Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
History
Origin
-
-
Discoverer
Alexandre Brongniart and René Just Haüy
R. J. Hauy
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From Greek pegma, pegmat which means- thing joined together + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock