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Gneiss vs Pseudotachylite


Pseudotachylite vs Gneiss


Definition

Definition
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  
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.  

History
  
  

Origin
-  
USA  

Discoverer
Unknown  
Unknown  

Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)  
From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.  

Class
Metamorphic Rocks  
Metamorphic Rocks  

Sub-Class
Durable Rock, Hard Rock  
Durable Rock, Hard Rock  

Family
  
  

Group
-  
-  

Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock  
Fine Grained Rock, Opaque Rock  

Texture

Texture
Banded, Foliated, Platy  
Quench  

Color
Black, Brown, Pink, Red, White  
Black, Brown, Green, Grey, Pink, White  

Maintenance
More  
Less  

Durability
Durable  
Durable  

Water Resistant
Yes  
Yes  

Scratch Resistant
Yes  
Yes  

Stain Resistant
Yes  
No  

Wind Resistant
Yes  
Yes  

Acid Resistant
No  
Yes  

Appearance
Foliated  
Dull and Soft  

Uses

Architecture
  
  

Interior Uses
Countertops, Decorative Aggregates, Flooring, 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  
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement  

Medical Industry
-  
-  

Antiquity Uses
Artifacts  
Artifacts, Monuments  

Other Uses
  
  

Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums  
Creating Artwork, Gemstone  

Types

Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.  
Cataclastic rock  

Features
Generally rough to touch, Is one of the oldest rock  
Host Rock for Lead  

Archaeological Significance
  
  

Monuments
-  
-  

Famous Monuments
Konark Sun Temple in India, Washington Monument, US  
-  

Sculpture
-  
-  

Famous Sculptures
-  
-  

Pictographs
-  
-  

Petroglyphs
-  
-  

Figurines
-  
-  

Fossils
Absent  
Absent  

Formation

Formation
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.   
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
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon  
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides  

Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide  
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur  

Transformation
  
  

Metamorphism
Yes  
Yes  

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

Weathering
Yes  
No  

Types of Weathering
Biological Weathering, Mechanical Weathering  
-  

Erosion
Yes  
No  

Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion  
-  

Properties

Physical Properties
  
  

Hardness
7  
7  

Grain Size
Medium to Coarse Grained  
Very fine-grained  

Fracture
Irregular  
Uneven  

Streak
White  
Light to dark brown  

Porosity
Very Less Porous  
Less Porous  

Luster
Dull  
Vitreous  

Compressive Strength
125.00 N/mm2  
25
60.00 N/mm2  
37

Cleavage
-  
-  

Toughness
1.2  
-  

Specific Gravity
2.5-2.7  
2.46-2.86  

Transparency
Translucent to Opaque  
Transparent to Translucent  

Density
2.6-2.9 g/cm3  
2.7-2.9 g/cm3  

Thermal Properties
  
  

Specific Heat Capacity
0.70 kJ/Kg K  
24
0.92 kJ/Kg K  
10

Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant  
Heat Resistant  

Reserves

Deposits in Eastern Continents
  
  

Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia  
South Korea  

Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo  
Western Africa  

Europe
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom  
Great Britain, Switzerland  

Others
-  
-  

Deposits in Western Continents
  
  

North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA  
-  

South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela  
-  

Deposits in Oceania Continent
  
  

Australia
New South Wales, New Zealand, Queensland, Victoria  
Central Australia, Western Australia  

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Gneiss vs Pseudotachylite Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Gneiss and Pseudotachylite Reserves. 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. Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Gneiss vs Pseudotachylite information and Gneiss vs Pseudotachylite characteristics in the upcoming sections.

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Gneiss vs Pseudotachylite Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Gneiss vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Pseudotachylite. Learn more about Gneiss vs Pseudotachylite in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Gneiss and Pseudotachylite, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.

More about Gneiss and Pseudotachylite

Here you can know more about Gneiss and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Pseudotachylite consists of mineral content and compound content. The mineral content of Gneiss includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Gneiss is available in black, brown, pink, red, white colors whereas, Pseudotachylite is available in black, brown, green, grey, pink, white colors. Appearance of Gneiss is Foliated and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Gneiss vs Pseudotachylite. Hardness of Gneiss and Pseudotachylite is 7. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Pseudotachylite are Cataclastic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss is white while that of Pseudotachylite is light to dark brown. The specific heat capacity of Gneiss is 0.70 kJ/Kg K and that of Pseudotachylite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Gneiss is heat resistant, pressure resistant, scratch resistant, wear resistant whereas Pseudotachylite is heat resistant.

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