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
Hornfels vs Anorthosite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Hornfels vs Anorthosite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Anorthosite. Learn more about Hornfels vs Anorthosite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Anorthosite include Decorative aggregates, Floor tiles, Homes and Interior decoration. Due to some exceptional properties of Hornfels and Anorthosite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Anorthosite include As dimension stone, Cement manufacture, For road aggregate.
More about Hornfels and Anorthosite
Here you can know more about Hornfels and Anorthosite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Anorthosite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Anorthosite includes Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Anorthosite, the texture, color and appearance plays an important role in determining the type of rock. 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. Appearance of Hornfels is Dull and that of Anorthosite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Hornfels vs Anorthosite. The hardness of Hornfels is 2-3 and that of Anorthosite is 5-6. The types of Hornfels are Biotite hornfels whereas types of Anorthosite are Proterozoic Anorthosite and Archean Anorthosite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is unknown while that of Anorthosite is white. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Anorthosite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Hornfels is heat resistant, impact resistant, pressure resistant whereas Anorthosite is heat resistant, impact resistant, pressure resistant, scratch resistant, wear resistant.
