Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature
Discoverer
Unknown
René Just Haüy
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From French, Greek eklogē selection with reference to the selective content of the rock + -ite1
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Not Yet Used
Medical Industry
Not Yet Used
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Creating Artwork, Gemstone
Creating Artwork, Gemstone
Types
Not Available
Not Available
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Not Yet Used
Formation
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.
Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Not Applicable
Types of Weathering
Not Applicable
Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Sea Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Uneven
Not Available
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Luster
Vitreous
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Irregular
Perfect
Toughness
Not Available
Not Available
Specific Gravity
2.46-2.86
2.86-2.87
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
3.2-3.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
South Korea
India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey
Africa
Western Africa
Ethiopia, Morocco, South Africa
Europe
Great Britain, Switzerland
France, Germany, Italy, Norway, Scotland
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Not Yet Found
Canada, Costa Rica, Panama, USA
South America
Not Yet Found
Argentina, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Central Australia, New Zealand, Queensland