1 Definition
1.1 Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Coquina is a sedimentary rock that is composed either wholly or almost entirely of the transported, abraded, and mechanically-sorted fragments of the shells of molluscs, trilobites, brachiopods, or other invertebrates
1.2 History
1.2.1 Origin
Unknown
European Foreland Basins
1.2.2 Discoverer
Alexandre Brongniart and René Just Haüy
Unknown
1.3 Etymology
From Greek trakhus rough’ or trakhutēs roughness
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
1.4 Class
Igneous Rocks
Sedimentary Rocks
1.4.1 Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock