Definition
Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Discoverer
René Just Haüy
Unknown
Etymology
From French, Greek eklogē selection with reference to the selective content of the rock + -ite1
From French schiste, Greek skhistos i.e. split
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy
Foliated, Platy
Color
Black, Brown, Green, Grey, Pink, White
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Durability
Durable
Durable
Appearance
Dull, Banded and Foilated
Layered and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Interior Decoration
Exterior Uses
Paving Stone, Garden Decoration
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
-
Construction Industry
-
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
Medical Industry
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
-
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
Creating Artwork, Gemstone
Used in aquariums, Writing Slates
Types
Eclogite
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
Easily splits into thin plates, Smooth to touch
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.
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Mineral Content
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Compound Content
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium
CaO, Carbon Dioxide, MgO
Types of Metamorphism
-
-
Types of Weathering
Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Shiny
Specific Gravity
2.86-2.87
2.5-2.9
Transparency
Opaque
Opaque
Density
3.2-3.6 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Africa
Ethiopia, Morocco, South Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Europe
France, Germany, Italy, Norway, Scotland
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Argentina, Brazil, Colombia, Ecuador
Brazil, Colombia, Guyana
Deposits in Oceania Continent
Australia
Central Australia, New Zealand, Queensland
New South Wales, New Zealand, Queensland