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
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 the Middle High German verb gneist (to spark; so called because the rock glitters)
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
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Foliated, Platy
Earthy
Color
Black, Brown, Pink, Red, White
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Dull, Banded and Foilated
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
Not Yet Used
Medical Industry
Not Yet Used
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Creating Artwork, Gemstone
Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Not Available
Features
Generally rough to touch, Is one of the oldest rock
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
Konark Sun Temple in India, Washington Monument, US
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
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.
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
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium
Types of Metamorphism
Impact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Chemical Erosion, Sea Erosion
Grain Size
Medium to Coarse Grained
Fine Grained
Fracture
Irregular
Not Available
Porosity
Very Less Porous
Less Porous
Luster
Dull
Subvitreous to Dull
Compressive Strength
Not Available
Toughness
1.2
Not Available
Specific Gravity
2.5-2.7
2.86-2.87
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.9 g/cm3
3.2-3.6 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Ethiopia, Morocco, South 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
France, Germany, Italy, Norway, Scotland
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, Costa Rica, Panama, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Argentina, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria
Central Australia, New Zealand, Queensland
Gneiss vs Eclogite 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 Eclogite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Eclogite. Learn more about Gneiss vs Eclogite in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Eclogite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Gneiss and Eclogite, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Eclogite include Not yet used.
More about Gneiss and Eclogite
Here you can know more about Gneiss and Eclogite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Eclogite 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 Eclogite includes Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Eclogite, 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, Eclogite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Gneiss is Foliated and that of Eclogite is Dull, Banded and Foilated. Properties of rock is another aspect for Gneiss vs Eclogite. The hardness of Gneiss is 7 and that of Eclogite is 3.5-4. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Eclogite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss and Eclogite is white. The specific heat capacity of Gneiss is Not Available and that of Eclogite is Not Available. 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 Eclogite is heat resistant.