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
Borolanite is a variety of Nepheline Syenite and belongs to igneous rocks and contains nepheline-alkali feldspar pseudomorphs which occur as conspicuous white spots in the dark rock matrix
From Alkalic Igneous complex near Loch Borralan in northwest Scotland
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock