Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Harzburgite is a plutonic rock of the peridotite group consisting largely of orthopyroxene and olivine
From the name of a town in Harzburg, Germany
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Opaque Rock
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