Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Origin
New Zealand
Brazil
Discoverer
Ferdinand von Hochstetter
Unknown
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
from French néphéline, from Greek nephelē
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phaneritic
Aphanitic
Color
Dark Greenish - Grey
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Skeletal
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Dunite
Peralkaline Nephelinite
Features
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Formation
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
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.
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Fine Grained
Porosity
Less Porous
Less Porous
Luster
Shiny
Vitreous to Metallic
Specific Gravity
3-3.01
2.4-2.9
Transparency
Translucent to Opaque
Opaque
Density
2.84-2.85 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Japan
Africa
Morocco, South Africa
Rwanda, Tanzania
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
-
All about Dunite and Nephelinite Properties
Know all about Dunite and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Dunite and Nephelinite belong to Igneous Rocks.Texture of Dunite is Phaneritic whereas that of Nephelinite is Aphanitic. Dunite appears Rough and Shiny and Nephelinite appears Skeletal. The luster of Dunite is shiny while that of Nephelinite is vitreous to metallic. Dunite is available in dark greenish - grey colors whereas Nephelinite is available in black, brown, green, grey, white colors. The commercial uses of Dunite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).