Schist and Skarn
Definition
Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
History
Origin
Unknown
USA, Australia
Discoverer
Unknown
Tornebohm
Etymology
From French schiste, Greek skhistos i.e. split
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
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
Fine Grained Rock, Opaque Rock
Texture
Texture
Foliated, Platy
Earthy, Mud-rich, Rough
Color
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Black, Brown, Colourless, Green, Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
No
Yes
Stain Resistant
No
No
Wind Resistant
No
Yes
Acid Resistant
No
Yes
Appearance
Layered and Shiny
Dull
Uses
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Not Yet Used
Curbing
Industry
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Not Applicable
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Used in aquariums, Writing Slates
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Types
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Endoskarns
Features
Easily splits into thin plates, Smooth to touch
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Used
Fossils
Absent
Absent
Formation
Formation
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Composition
Mineral Content
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
CaO, Carbon Dioxide, MgO
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Transformation
Metamorphism
No
Yes
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
Yes
No
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Erosion
Yes
No
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Not Applicable
Properties
Physical Properties
Hardness
3.5-4
6.5
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Irregular
Streak
White
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Shiny
Waxy and Dull
Cleavage
Slaty
Slaty
Toughness
1.5
2.4
Specific Gravity
2.5-2.9
2.86
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.8-2.9 g/cm3
Thermal Properties
Specific Heat Capacity
Not Available
0.92 kJ/Kg K
10
Resistance
Impact Resistant, Pressure Resistant, Water Resistant
Heat Resistant
Reserves
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
South Africa, Western Africa
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada
South America
Brazil, Colombia, Guyana
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
Central Australia, Western Australia
All about Schist and Skarn Properties
Know all about Schist and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Schist and Skarn belong to Metamorphic Rocks.Texture of Schist is Foliated, Platy whereas that of Skarn is Earthy, Mud-rich, Rough. Schist appears Layered and Shiny and Skarn appears Dull. The luster of Schist is shiny while that of Skarn is waxy and dull. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas Skarn is available in black, brown, colourless, green, grey, white colors. The commercial uses of Schist are used in aquariums, writing slates and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).
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