Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
Discoverer
Unknown
Alexandre Brongniart
Etymology
From French anorthose plagioclase + -ite1
From Amphibole + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated, Glassy
Banded, Foliated, Massive
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Brown, Green, Grey
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Foliated
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Curling
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Proterozoic Anorthosite and Archean Anorthosite
Hornblendite
Features
Generally rough to touch, Is one of the oldest rock
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
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.
Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
-
Types of Weathering
Biological Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Grain Size
Coarse Grained
Medium to Coarse Grained
Fracture
Irregular
Irregular to Conchoidal
Streak
White
White to Grey
Porosity
Less Porous
Less Porous
Luster
Pearly to Subvitreous
Vitreous to Dull
Specific Gravity
2.62-2.82
2.5
Transparency
Translucent
Opaque
Density
2.7-4 g/cm3
2.85-3.07 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
-
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Germany, Greece, Iceland, Norway, Poland
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
South Australia, Western Australia
Anorthosite vs Amphibolite 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. Anorthosite vs Amphibolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Anorthosite and Properties of Amphibolite. Learn more about Anorthosite vs Amphibolite in the next section. The interior uses of Anorthosite include Decorative aggregates, Floor tiles, Homes and Interior decoration whereas the interior uses of Amphibolite include Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Anorthosite and Amphibolite, they have various applications in construction industry. The uses of Anorthosite in construction industry include As dimension stone, Cement manufacture, For road aggregate and that of Amphibolite include As dimension stone, Building houses or walls, Cobblestones, Construction aggregate, For road aggregate, Landscaping, Production of glass and ceramics, Roadstone.
More about Anorthosite and Amphibolite
Here you can know more about Anorthosite and Amphibolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Anorthosite and Amphibolite consists of mineral content and compound content. The mineral content of Anorthosite includes Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene and mineral content of Amphibolite includes Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite. You can also check out the list of all Igneous Rocks. When we have to compare Anorthosite vs Amphibolite, the texture, color and appearance plays an important role in determining the type of rock. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors whereas, Amphibolite is available in black, brown, green, grey colors. Appearance of Anorthosite is Layered, Banded, Veined and Shiny and that of Amphibolite is Foliated. Properties of rock is another aspect for Anorthosite vs Amphibolite. The hardness of Anorthosite is 5-6 and that of Amphibolite is 6-7. The types of Anorthosite are Proterozoic Anorthosite and Archean Anorthosite whereas types of Amphibolite are Hornblendite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Anorthosite is white while that of Amphibolite is white to grey. The specific heat capacity of Anorthosite is 0.84 kJ/Kg K and that of Amphibolite 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.Anorthosite is heat resistant, impact resistant, pressure resistant, scratch resistant, wear resistant whereas Amphibolite is heat resistant, pressure resistant, wear resistant.