Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
History
Origin
-
USA
Discoverer
Unknown
Unknown
Etymology
From French anorthose plagioclase + -ite1
From 17th century, because of its greasy feel and use like a soap
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated, Glassy
Polished
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Black to Grey, Green, Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Layered, Banded, Veined and Shiny
Dull, Banded and Foilated
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
Other Uses
Commercial Uses
Creating Artwork, Curling
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
Types
Proterozoic Anorthosite and Archean Anorthosite
Metamorphic rock
Features
Generally rough to touch, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
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.
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
Composition
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
CaO, Mg, MgO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Wind Erosion
-
Physical Properties
Hardness
5-61
1
7
👆🏻
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Streak
White
Black
Porosity
Less Porous
Less Porous
Luster
Pearly to Subvitreous
Greasy
Compressive Strength
180.00 N/mm2225.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
-
1
Specific Gravity
2.62-2.822.86
0
8.4
👆🏻
Transparency
Translucent
Opaque
Density
2.7-4 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.88 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
-
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Africa
-
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Others
-
-
Deposits in Western Continents
North America
Canada
Canada, USA
South America
Bolivia, Colombia
Colombia
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
Central Australia, New Zealand, Queensland