Greenschist and Gneiss
Definition
Definition
Greenschist is a metamorphic rock that is formed under lowest temperatures and pressures and is usually produced by regional metamorphism
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
History
Discoverer
Unknown
Unknown
Etymology
From minerals such as chlorite, serpentine, and epidote, and platy minerals such as muscovite and platy serpentine which are green in color
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Not Applicable
Not Applicable
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Texture
Foliated, Platy
Banded, Foliated, Platy
Color
Dark Greenish - Grey, Green
Black, Brown, Pink, Red, White
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
No
Yes
Wind Resistant
No
Yes
Acid Resistant
No
No
Appearance
Layered and Shiny
Foliated
Uses
Architecture
Interior Uses
Bathrooms, Countertops, Decorative Aggregates, Entryways, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Cutting Tool, for Road Aggregate, Roadstone
As Dimension Stone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts
Other Uses
Commercial Uses
Blackboards, Manufacture of tools, Writing Slates
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Types
Not Available
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Easily splits into thin plates, Smooth to touch
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Konark Sun Temple in India, Washington Monument, US
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Not Yet Used
Fossils
Absent
Absent
Formation
Formation
Greenschist is medium grade metamorphic rock, formed by the metamorphosis of mudstone or shale, or some types of igneous rock, when it is subjected to higher temperatures and pressures.
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.
Composition
Mineral Content
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Serpentine, Sillimanite, Staurolite, Talc
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
CaO, Carbon Dioxide, MgO
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
No
Yes
Types of Metamorphism
Not Applicable
Impact Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Mechanical Weathering
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Properties
Physical Properties
Hardness
3.5-4
7
Grain Size
Medium to Fine Coarse Grained
Medium to Coarse Grained
Fracture
Conchoidal
Irregular
Streak
White
White
Porosity
Highly Porous
Very Less Porous
Luster
Shiny
Dull
Compressive Strength
Not Available
125.00 N/mm2
17
Cleavage
Slaty
Poor
Toughness
1.5
1.2
Specific Gravity
2.5-2.9
2.5-2.7
Transparency
Opaque
Translucent to Opaque
Density
2.8-2.9 g/cm3
2.6-2.9 g/cm3
Thermal Properties
Resistance
Impact Resistant, Pressure Resistant, Water Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Reserves
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Brazil, Colombia, Guyana
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
New South Wales, New Zealand, Queensland, Victoria
All about Greenschist and Gneiss Properties
Know all about Greenschist and Gneiss properties here. All properties of rocks are important as they define the type of rock and its application. Greenschist and Gneiss belong to Metamorphic Rocks.Texture of Greenschist is Foliated, Platy whereas that of Gneiss is Banded, Foliated, Platy. Greenschist appears Layered and Shiny and Gneiss appears Foliated. The luster of Greenschist is shiny while that of Gneiss is dull. Greenschist is available in dark greenish - grey, green colors whereas Gneiss is available in black, brown, pink, red, white colors. The commercial uses of Greenschist are blackboards, manufacture of tools, writing slates and that of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums.
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