Definition
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
New Zealand
-
Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
From German which means hornstone
From Greek trakhus rough’ or trakhutēs roughness
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock