Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate
Discoverer
Unknown
Unknown
Etymology
From French anorthose plagioclase + -ite1
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated, Glassy
Clastic, Polished
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Dark Grey to Black, Pink, Red, White
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Rough and Dull
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Used for flooring, stair treads, borders and window sills.
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Curling
Fire resistant, Used to manufracture paperweights and bookends
Types
Proterozoic Anorthosite and Archean Anorthosite
Metamorphic rock
Features
Generally rough to touch, Is one of the oldest rock
Is one of the oldest 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.
An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
-
Types of Weathering
Biological Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Wind Erosion
Chemical Erosion
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal to Uneven
Streak
White
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Pearly to Subvitreous
Waxy and Dull
Specific Gravity
2.62-2.82
2.56-2.68
Transparency
Translucent
Opaque
Density
2.7-4 g/cm3
2.54-2.66 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
-
Bangladesh, China, India, Russia
Africa
-
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
South America
Bolivia, Colombia
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
All about Anorthosite and Argillite Properties
Know all about Anorthosite and Argillite properties here. All properties of rocks are important as they define the type of rock and its application. Anorthosite belongs to Igneous Rocks while Argillite belongs to Sedimentary Rocks.Texture of Anorthosite is Foliated, Glassy whereas that of Argillite is Clastic, Polished. Anorthosite appears Layered, Banded, Veined and Shiny and Argillite appears Rough and Dull. The luster of Anorthosite is pearly to subvitreous while that of Argillite is waxy and dull. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors whereas Argillite is available in dark grey to black, pink, red, white colors. The commercial uses of Anorthosite are creating artwork, curling and that of Argillite are fire resistant, used to manufracture paperweights and bookends.