Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Appinite is an igneous rock in which the crystals are so fine grained that individual minerals cannot be easily distinguished
History
Origin
-
-
Discoverer
Alexandre Brongniart and René Just Haüy
Unknown
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock