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Hornfels and Eclogite


Eclogite and Hornfels


Definition

Definition
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock  
Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature  

History
  
  

Origin
New Zealand  
-  

Discoverer
Unknown  
René Just Haüy  

Etymology
From German which means hornstone  
From French, Greek eklogē selection with reference to the selective content of the rock + -ite1  

Class
Metamorphic Rocks  
Metamorphic Rocks  

Sub-Class
Durable Rock, Soft Rock  
Durable Rock, Medium Hardness Rock  

Family
  
  

Group
-  
-  

Other Categories
Fine Grained Rock, Opaque Rock  
Fine Grained Rock, Opaque Rock  

Texture

Texture
Granular, Platy  
Earthy  

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

Maintenance
Less  
Less  

Durability
Durable  
Durable  

Water Resistant
Yes  
No  

Scratch Resistant
No  
Yes  

Stain Resistant
No  
Yes  

Wind Resistant
No  
Yes  

Acid Resistant
No  
No  

Appearance
Dull  
Dull, Banded and Foilated  

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration  
Decorative Aggregates, Interior Decoration  

Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone  
Paving Stone, Garden Decoration  

Other Architectural Uses
Curbing  
Curbing  

Industry
  
  

Construction Industry
for Road Aggregate, Roadstone  
-  

Medical Industry
-  
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics  

Antiquity Uses
Artifacts, Monuments  
Artifacts  

Other Uses
  
  

Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork  
Creating Artwork, Gemstone  

Types

Types
Biotite hornfels  
Eclogite  

Features
Smooth to touch  
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock  

Archaeological Significance
  
  

Monuments
-  
-  

Famous Monuments
-  
-  

Sculpture
-  
-  

Famous Sculptures
-  
-  

Pictographs
-  
-  

Petroglyphs
-  
-  

Figurines
-  
-  

Fossils
Absent  
Absent  

Formation

Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.  
Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.  

Composition
  
  

Mineral Content
Andalusite  
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite  

Compound Content
Fe, Mg  
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium  

Transformation
  
  

Metamorphism
No  
No  

Types of Metamorphism
-  
-  

Weathering
Yes  
Yes  

Types of Weathering
Biological Weathering  
Mechanical Weathering  

Erosion
Yes  
Yes  

Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion  
Chemical Erosion, Sea Erosion  

Properties

Physical Properties
  
  

Hardness
2-3  
3.5-4  

Grain Size
Fine Grained  
Fine Grained  

Fracture
Conchoidal  
-  

Streak
-  
White  

Porosity
Highly Porous  
Less Porous  

Luster
Shiny  
Subvitreous to Dull  

Compressive Strength
5.80 N/mm2  
99+
200.00 N/mm2  
13

Cleavage
Perfect  
Perfect  

Toughness
-  
-  

Specific Gravity
3.4-3.9  
2.86-2.87  

Transparency
Opaque  
Opaque  

Density
0.25-0.30 g/cm3  
3.2-3.6 g/cm3  

Thermal Properties
  
  

Specific Heat Capacity
0.84 kJ/Kg K  
15
0.75 kJ/Kg K  
20

Resistance
Heat Resistant, Impact Resistant, Pressure Resistant  
Heat Resistant  

Reserves

Deposits in Eastern Continents
  
  

Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand  
India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey  

Africa
Cameroon, East Africa, Tanzania, Western Africa  
Ethiopia, Morocco, South Africa  

Europe
United Kingdom  
France, Germany, Italy, Norway, Scotland  

Others
-  
Greenland  

Deposits in Western Continents
  
  

North America
Canada, USA  
Canada, Costa Rica, Panama, USA  

South America
Bolivia, Brazil, Colombia, Ecuador  
Argentina, Brazil, Colombia, Ecuador  

Deposits in Oceania Continent
  
  

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

Summary >>
<< Reserves

All about Hornfels and Eclogite Properties

Know all about Hornfels and Eclogite properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels and Eclogite belong to Metamorphic Rocks.Texture of Hornfels is Granular, Platy whereas that of Eclogite is Earthy. Hornfels appears Dull and Eclogite appears Dull, Banded and Foilated. The luster of Hornfels is shiny while that of Eclogite is subvitreous to dull. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Eclogite is available in black, brown, green, grey, pink, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Eclogite are creating artwork, gemstone.

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