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
  
History
  
  
Origin
New Zealand
  
Unknown
  
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
  
Family
  
  
Group
Plutonic
  
Not Applicable
  
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
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Rough and Shiny
  
Foliated
  
Architecture
  
  
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
  
Industry
  
  
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
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
  
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
  
Types
Not Available
  
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
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Konark Sun Temple in India, Washington Monument, US
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
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.
  
Composition
  
  
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
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
  
Chemical Erosion, Coastal Erosion, Sea Erosion
  
Physical Properties
  
  
Hardness
3.5-4
  
7
  
Grain Size
Coarse Grained
  
Medium to Coarse Grained
  
Fracture
Irregular
  
Irregular
  
Streak
White
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Shiny
  
Dull
  
Compressive Strength
107.55 N/mm2
  
19
125.00 N/mm2
  
17
Cleavage
Imperfect
  
Poor
  
Toughness
2.1
  
1.2
  
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
  
Thermal Properties
  
  
Specific Heat Capacity
1.25 kJ/Kg K
  
6
Not Available
  
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, Venezuela
  
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
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