Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
  
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
  
History
  
  
Origin
New Zealand
  
Ethiopia
  
Discoverer
Ferdinand von Hochstetter
  
Obsius
  
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
  
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Opaque Rock
  
Texture
Phaneritic
  
Glassy
  
Color
Dark Greenish - Grey
  
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
No
  
Appearance
Rough and Shiny
  
Shiny
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Garden Decoration
  
Other Architectural Uses
Curbing
  
Not Yet Used
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
  
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
  
Medical Industry
Not Yet Used
  
Surgery
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts, Jewellery
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
  
Creating Artwork, Mirror, Used in aquariums
  
Types
Not Available
  
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
  
Features
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
  
Blocks negativity, Helps to protect against depression
  
Archaeological Significance
  
  
Monuments
Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
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.
  
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
  
Composition
  
  
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
  
Not Available
  
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
3.5-4
  
5-5.5
  
Grain Size
Coarse Grained
  
Not Applicable
  
Fracture
Irregular
  
Conchoidal
  
Streak
White
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Shiny
  
Vitreous
  
Compressive Strength
107.55 N/mm2
  
19
Cleavage
Imperfect
  
Non-Existent
  
Toughness
2.1
  
Not Available
  
Specific Gravity
3-3.01
  
2.6-2.7
  
Transparency
Translucent to Opaque
  
Translucent
  
Density
2.84-2.85 g/cm3
  
2.6 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
1.25 kJ/Kg K
  
6
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
  
Afghanistan, Indonesia, Japan, Russia
  
Africa
Morocco, South Africa
  
Kenya
  
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland, Venezuela
  
Greece, Hungary, Iceland, Italy, Turkey
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, Mexico, USA
  
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
  
Argentina, Chile, Ecuador, Peru
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Western Australia
  
New Zealand