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
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
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
Quench
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull
Dull and Soft
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
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone
Types
Biotite hornfels
Not Available
Features
Smooth to touch
Host Rock for Lead
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Not Yet 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. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Andalusite
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Fe, Mg
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
Unknown
Light to dark brown
Porosity
Highly Porous
Less Porous
Cleavage
Perfect
Irregular
Toughness
Not Yet Found
Not Available
Specific Gravity
3.4-3.9
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
0.25-0.30 g/cm3
2.7-2.9 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
South Korea
Africa
Cameroon, East Africa, Tanzania, Western Africa
Western Africa
Europe
United Kingdom
Great Britain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Not Yet Found
South America
Bolivia, Brazil, Colombia, Ecuador
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
Central Australia, Western Australia
All about Hornfels and Pseudotachylite Properties
Know all about Hornfels and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels and Pseudotachylite belong to Metamorphic Rocks.Texture of Hornfels is Granular, Platy whereas that of Pseudotachylite is Quench. Hornfels appears Dull and Pseudotachylite appears Dull and Soft. The luster of Hornfels is shiny while that of Pseudotachylite is vitreous. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Pseudotachylite are creating artwork, gemstone.