Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Origin
Brazil
New Zealand
Discoverer
Unknown
Ferdinand von Hochstetter
Etymology
from French néphéline, from Greek nephelē
From the name of Dun Mountain, New Zealand, + -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
Phaneritic
Color
Black, Brown, Colourless, Green, Grey, White
Dark Greenish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Rough and Shiny
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Types
Peralkaline Nephelinite
Not Available
Features
Host Rock for Lead
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
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.
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Compound Content
Ca, CaO, Carbon, Cl, MgO
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Fine Grained
Coarse Grained
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Shiny
Cleavage
Imperfect
Imperfect
Specific Gravity
2.4-2.9
3-3.01
Transparency
Opaque
Translucent to Opaque
Density
2.5-3 g/cm3
2.84-2.85 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Japan
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Africa
Rwanda, Tanzania
Morocco, South Africa
Europe
Not Yet Found
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland, Venezuela
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Argentina, Brazil, Colombia, Ecuador, Venezuela
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand, Western Australia
All about Nephelinite and Dunite Properties
Know all about Nephelinite and Dunite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Dunite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Dunite is Phaneritic. Nephelinite appears Skeletal and Dunite appears Rough and Shiny. The luster of Nephelinite is vitreous to metallic while that of Dunite is shiny. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Dunite is available in dark greenish - grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Dunite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.