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Dunite and Pseudotachylite


Pseudotachylite and Dunite


Definition

Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine   
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.   

History
  
  

Origin
New Zealand   
USA   

Discoverer
Ferdinand von Hochstetter   
Unknown   

Etymology
From the name of Dun Mountain, New Zealand, + -ite1   
From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.   

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   
Fine Grained Rock, Opaque Rock   

Texture

Texture
Phaneritic   
Quench   

Color
Dark Greenish - Grey   
Black, Brown, Colourless, Green, Grey, Pink, White   

Maintenance
Less   
Less   

Durability
Durable   
Durable   

Water Resistant
Yes   
Yes   

Scratch Resistant
Yes   
Yes   

Stain Resistant
Yes   
No   

Wind Resistant
No   
Yes   

Acid Resistant
No   
Yes   

Appearance
Rough and Shiny   
Dull and Soft   

Uses

Architecture
  
  

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   

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, Cement Manufacture, for Road Aggregate, Making natural cement   

Medical Industry
Not Yet Used   
Not Yet Used   

Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines   
Artifacts, Monuments   

Other Uses
  
  

Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds   
Creating Artwork, Gemstone   

Types

Types
Not Available   
Not Available   

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
  
  

Monuments
Used   
Used   

Famous Monuments
Data Not Available   
Data Not Available   

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

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. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.   

Composition
  
  

Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene   
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides   

Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide   
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur   

Transformation
  
  

Metamorphism
Yes   
Yes   

Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism   
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism   

Weathering
Yes   
No   

Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering   
Not Applicable   

Erosion
Yes   
No   

Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion   
Not Applicable   

Properties

Physical Properties
  
  

Hardness
3.5-4   
7   

Grain Size
Coarse Grained   
Very fine-grained   

Fracture
Irregular   
Uneven   

Streak
White   
Light to dark brown   

Porosity
Less Porous   
Less Porous   

Luster
Shiny   
Vitreous   

Compressive Strength
107.55 N/mm2   
19
60.00 N/mm2   
25

Cleavage
Imperfect   
Irregular   

Toughness
2.1   
Not Available   

Specific Gravity
3-3.01   
2.46-2.86   

Transparency
Translucent to Opaque   
Transparent to Translucent   

Density
2.84-2.85 g/cm3   
2.7-2.9 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   

Reserves

Deposits in Eastern Continents
  
  

Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey   
South Korea   

Africa
Morocco, South Africa   
Western Africa   

Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland, Venezuela   
Great Britain, Switzerland   

Others
Not Yet Found   
Not Yet Found   

Deposits in Western Continents
  
  

North America
Canada, USA   
Not Yet Found   

South America
Argentina, Brazil, Colombia, Ecuador, Venezuela   
Not Yet Found   

Deposits in Oceania Continent
  
  

Australia
New Zealand, Western Australia   
Central Australia, Western Australia   

Summary >>
<< Reserves

All about Dunite and Pseudotachylite Properties

Know all about Dunite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Dunite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Dunite is Phaneritic whereas that of Pseudotachylite is Quench. Dunite appears Rough and Shiny and Pseudotachylite appears Dull and Soft. The luster of Dunite is shiny while that of Pseudotachylite is vitreous. Dunite is available in dark greenish - grey colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Dunite and Pseudotachylite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.

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