Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
Origin
New Zealand
USA, Australia
Discoverer
Ferdinand von Hochstetter
Tornebohm
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Igneous Rocks
Metamorphic 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
Earthy, Mud-rich, Rough
Color
Dark Greenish - Grey
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Dull
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, 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, Making natural cement, Raw material for the manufacture of mortar
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
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, Zinc and Copper Deposits
Archaeological Significance
Formation
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
-
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Irregular
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Shiny
Waxy and Dull
Specific Gravity
3-3.01
2.86
Transparency
Translucent to Opaque
Opaque
Density
2.84-2.85 g/cm3
2.8-2.9 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
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Morocco, South Africa
South Africa, Western Africa
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Central Australia, Western Australia
All about Dunite and Skarn Properties
Know all about Dunite and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Dunite belongs to Igneous Rocks while Skarn belongs to Metamorphic Rocks.Texture of Dunite is Phaneritic whereas that of Skarn is Earthy, Mud-rich, Rough. Dunite appears Rough and Shiny and Skarn appears Dull. The luster of Dunite is shiny while that of Skarn is waxy and dull. Dunite is available in dark greenish - grey colors whereas Skarn 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 Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).