Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Unknown
Unknown
Etymology
From French anorthose plagioclase + -ite1
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated, Glassy
Quench
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Dull and Soft
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Creating Artwork, Curling
Creating Artwork, Gemstone
Types
Proterozoic Anorthosite and Archean Anorthosite
Cataclastic rock
Features
Generally rough to touch, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
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.
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
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering
-
Types of Erosion
Chemical Erosion, Wind Erosion
-
Grain Size
Coarse Grained
Very fine-grained
Fracture
Irregular
Uneven
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Pearly to Subvitreous
Vitreous
Specific Gravity
2.62-2.82
2.46-2.86
Transparency
Translucent
Transparent to Translucent
Density
2.7-4 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Great Britain, Switzerland
Deposits in Western Continents
South America
Bolivia, Colombia
-
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
Central Australia, Western Australia
All about Anorthosite and Pseudotachylite Properties
Know all about Anorthosite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Anorthosite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Anorthosite is Foliated, Glassy whereas that of Pseudotachylite is Quench. Anorthosite appears Layered, Banded, Veined and Shiny and Pseudotachylite appears Dull and Soft. The luster of Anorthosite is pearly to subvitreous while that of Pseudotachylite is vitreous. Anorthosite and Pseudotachylite are available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors. The commercial uses of Anorthosite are creating artwork, curling and that of Pseudotachylite are creating artwork, gemstone.