Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
Discoverer
Ferdinand von Hochstetter
Unknown
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Phaneritic
Banded, Foliated, Platy
Color
Dark Greenish - Grey
Black, Brown, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Foliated
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, 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 Dimension Stone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Dunite
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Famous Monuments
-
Konark Sun Temple in India, Washington Monument, US
Formation
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Grain Size
Coarse Grained
Medium to Coarse Grained
Fracture
Irregular
Irregular
Porosity
Less Porous
Very Less Porous
Specific Gravity
3-3.01
2.5-2.7
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.84-2.85 g/cm3
2.6-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Morocco, South Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, New Zealand, Queensland, Victoria