Definition
Novaculite is a dense, hard, fine-grained, siliceous metamorpic rock which is a type of chert that breaks with conchoidal fracture
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
-
-
Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
From Latin word novacula, for razor stone
From Greek trakhus rough’ or trakhutēs roughness
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock