Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Alexandre Brongniart and René Just Haüy
From Greek trakhus rough’ or trakhutēs roughness
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
From Greek anthrakites, from anthrax, anthrak meaning coal
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock