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
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
Origin
New Zealand
USA, Australia
Discoverer
Unknown
Tornebohm
Etymology
From German which means hornstone
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular, Platy
Earthy, Mud-rich, Rough
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Not Applicable
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Biotite hornfels
Endoskarns
Features
Smooth to touch
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Used
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Andalusite
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Fe, Mg
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Not Applicable
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Not Applicable
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Irregular
Streak
Unknown
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Shiny
Waxy and Dull
Compressive Strength
Not Available
Toughness
Not Yet Found
2.4
Specific Gravity
3.4-3.9
2.86
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Cameroon, East Africa, Tanzania, Western Africa
South Africa, Western Africa
Europe
United Kingdom
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Bolivia, Brazil, Colombia, Ecuador
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
Central Australia, Western Australia
All about Hornfels and Skarn Properties
Know all about Hornfels and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels and Skarn belong to Metamorphic Rocks.Texture of Hornfels is Granular, Platy whereas that of Skarn is Earthy, Mud-rich, Rough. Hornfels appears Dull and Skarn appears Dull. The luster of Hornfels is shiny while that of Skarn is waxy and dull. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Skarn is available in black, brown, colourless, green, grey, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).