Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
Origin
-
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
From French anorthose plagioclase + -ite1
From Adak, Aleutian Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated, Glassy
Porphyritic
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Dull and Soft
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Curling
Commemorative Tablets, Pottery, Used in aquariums
Types
Proterozoic Anorthosite and Archean Anorthosite
Intermediate volcanic rock
Features
Generally rough to touch, Is one of the oldest rock
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
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.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Olivine, Plagioclase, Pyroxene
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Coarse Grained
Fine to Medium Grained
Fracture
Irregular
Conchoidal
Streak
White
Bluish Black
Porosity
Less Porous
Less Porous
Luster
Pearly to Subvitreous
Grainy, Pearly and Vitreous
Specific Gravity
2.62-2.82
-9999
Transparency
Translucent
Opaque
Density
2.7-4 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
-
Ethiopia, Somalia, South Africa
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Iceland
Deposits in Western Continents
North America
Canada
Canada, USA
South America
Bolivia, Colombia
Brazil
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
-
All about Anorthosite and Adakite Properties
Know all about Anorthosite and Adakite properties here. All properties of rocks are important as they define the type of rock and its application. Anorthosite and Adakite belong to Igneous Rocks.Texture of Anorthosite is Foliated, Glassy whereas that of Adakite is Porphyritic. Anorthosite appears Layered, Banded, Veined and Shiny and Adakite appears Dull and Soft. The luster of Anorthosite is pearly to subvitreous while that of Adakite is grainy, pearly and vitreous. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors whereas Adakite is available in black, brown, light to dark grey colors. The commercial uses of Anorthosite are creating artwork, curling and that of Adakite are commemorative tablets, pottery, used in aquariums.