Definition
Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Discoverer
René Just Haüy
Unknown
Etymology
From French, Greek eklogē selection with reference to the selective content of the rock + -ite1
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy
Banded, Rough
Color
Black, Brown, Green, Grey, Pink, White
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Glassy or Pearly
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
-
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
-
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Creating Artwork, Gemstone
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Eclogite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Formation
Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Mineral Content
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite
Quartz, Silicon
Compound Content
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium
Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Sea Erosion
Chemical Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
-
Uneven, Splintery or Conchoidal
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Waxy and Dull
Specific Gravity
2.86-2.87
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
3.2-3.6 g/cm3
2.7 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Ethiopia, Morocco, South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
France, Germany, Italy, Norway, Scotland
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Greenland
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada, Mexico, USA
South America
Argentina, Brazil, Colombia, Ecuador
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Central Australia, New Zealand, Queensland
New South Wales, Queensland, South Australia, Western Australia
All about Eclogite and Chert Properties
Know all about Eclogite and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Eclogite belongs to Metamorphic Rocks while Chert belongs to Sedimentary Rocks.Texture of Eclogite is Earthy whereas that of Chert is Banded, Rough. Eclogite appears Dull, Banded and Foilated and Chert appears Glassy or Pearly. The luster of Eclogite is subvitreous to dull while that of Chert is waxy and dull. Eclogite is available in black, brown, green, grey, pink, white colors whereas Chert is available in black, brown, green, grey, red, white colors. The commercial uses of Eclogite are creating artwork, gemstone and that of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.