Adakite and Skarn
Definition
Definition
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
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
Adak, Aleutian Islands
USA, Australia
Discoverer
Defant and Drummond
Tornebohm
Etymology
From Adak, Aleutian Islands
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Texture
Porphyritic
Earthy, Mud-rich, Rough
Color
Black, Brown, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
No
Yes
Scratch Resistant
No
Yes
Stain Resistant
No
No
Wind Resistant
Yes
Yes
Acid Resistant
Yes
Yes
Appearance
Dull and Soft
Dull
Uses
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Whetstones
Curbing
Industry
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, 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
Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Types
Not Available
Endoskarns
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Monuments
Used
Used
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Used
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Used
Fossils
Absent
Absent
Formation
Formation
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
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
Olivine, Plagioclase, Pyroxene
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Transformation
Metamorphism
Yes
Yes
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
Yes
No
Types of Weathering
Chemical Weathering, Mechanical Weathering
Not Applicable
Erosion
Yes
No
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Not Applicable
Properties
Physical Properties
Hardness
3-4
6.5
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Irregular
Streak
Bluish Black
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Grainy, Pearly and Vitreous
Waxy and Dull
Cleavage
Not Available
Slaty
Toughness
Not Available
2.4
Specific Gravity
Not Available
2.86
Transparency
Opaque
Opaque
Density
Not Available
2.8-2.9 g/cm3
Thermal Properties
Specific Heat Capacity
Not Available
0.92 kJ/Kg K
10
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Reserves
Deposits in Eastern Continents
Asia
India, Russia
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Ethiopia, Somalia, South Africa
South Africa, Western Africa
Europe
Iceland
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Brazil
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, Western Australia
All about Adakite and Skarn Properties
Know all about Adakite and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Adakite belongs to Igneous Rocks while Skarn belongs to Metamorphic Rocks.Texture of Adakite is Porphyritic whereas that of Skarn is Earthy, Mud-rich, Rough. Adakite appears Dull and Soft and Skarn appears Dull. The luster of Adakite is grainy, pearly and vitreous while that of Skarn is waxy and dull. Adakite is available in black, brown, light to dark grey colors whereas Skarn is available in black, brown, colourless, green, grey, white colors. The commercial uses of Adakite are commemorative tablets, pottery, used in aquariums and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).
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