Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From French anorthose plagioclase + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Aphanitic
Foliated, Glassy
Color
Black, Brown, Colourless, Green, Grey, White
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Durability
Durable
Durable
Appearance
Skeletal
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Creating Artwork, Curling
Types
Peralkaline Nephelinite
Proterozoic Anorthosite and Archean Anorthosite
Features
Host Rock for Lead
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Formation
Nephelinite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Compound Content
Ca, CaO, Carbon, Cl, MgO
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Types of Metamorphism
Contact Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Wind Erosion
Grain Size
Fine Grained
Coarse Grained
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Pearly to Subvitreous
Compressive Strength
Not Available
Cleavage
Imperfect
Irregular
Toughness
2.7
Not Available
Specific Gravity
2.4-2.9
2.62-2.82
Transparency
Opaque
Translucent
Density
2.5-3 g/cm3
2.7-4 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
Not Yet Found
Europe
Not Yet Found
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Colombia
Bolivia, Colombia
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, South Australia, Western Australia
All about Nephelinite and Anorthosite Properties
Know all about Nephelinite and Anorthosite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Anorthosite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Anorthosite is Foliated, Glassy. Nephelinite appears Skeletal and Anorthosite appears Layered, Banded, Veined and Shiny. The luster of Nephelinite is vitreous to metallic while that of Anorthosite is pearly to subvitreous. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Anorthosite are creating artwork, curling.