Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
From the locality in Essex County, Massachusetts,US
Fine Grained Rock, Opaque Rock
Shonkinite is a rare, dark-coloured and intrusive igneous rock which contains augite and orthoclase feldspar as its primary constituents
From the name of Shonkin Sag ranges in the Highwood Mountains of north-central Montana, US
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock