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
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Origin
New Zealand
Unknown
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From French anorthose plagioclase + -ite1
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Granular, Platy
Foliated, Glassy
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, 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
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Curling
Types
Biotite hornfels
Proterozoic Anorthosite and Archean Anorthosite
Features
Smooth to touch
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Not Applicable
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.
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
Mineral Content
Andalusite
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Compound Content
Fe, Mg
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Types of Metamorphism
Not Applicable
Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Wind Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Highly Porous
Less Porous
Luster
Shiny
Pearly to Subvitreous
Compressive Strength
Not Available
Cleavage
Perfect
Irregular
Toughness
Not Yet Found
Not Available
Specific Gravity
3.4-3.9
2.62-2.82
Transparency
Opaque
Translucent
Density
0.25-0.30 g/cm3
2.7-4 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Not Yet Found
Africa
Cameroon, East Africa, Tanzania, Western Africa
Not Yet Found
Europe
United Kingdom
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Bolivia, Brazil, Colombia, Ecuador
Bolivia, Colombia
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
Central Australia, South Australia, Western Australia
All about Hornfels and Anorthosite Properties
Know all about Hornfels and Anorthosite properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Anorthosite belongs to Igneous Rocks.Texture of Hornfels is Granular, Platy whereas that of Anorthosite is Foliated, Glassy. Hornfels appears Dull and Anorthosite appears Layered, Banded, Veined and Shiny. The luster of Hornfels is shiny while that of Anorthosite is pearly to subvitreous. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Anorthosite are creating artwork, curling.