Adakite and Schist
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
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
History
Origin
Adak, Aleutian Islands
Unknown
Discoverer
Defant and Drummond
Unknown
Etymology
From Adak, Aleutian Islands
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Texture
Porphyritic
Foliated, Platy
Color
Black, Brown, Light to Dark Grey
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
No
Yes
Scratch Resistant
No
No
Stain Resistant
No
No
Wind Resistant
Yes
No
Acid Resistant
Yes
No
Appearance
Dull and Soft
Layered and Shiny
Uses
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Floor Tiles, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
Garden Decoration, Paving Stone
Other Architectural Uses
Whetstones
Not Yet Used
Industry
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Monuments, Sculpture, Small Figurines
Artifacts
Other Uses
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
Used in aquariums, Writing Slates
Types
Types
Not Available
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Easily splits into thin plates, Smooth to touch
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Used
Petroglyphs
Used
Used
Figurines
Used
Not Yet 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.
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Composition
Mineral Content
Olivine, Plagioclase, Pyroxene
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
CaO, Carbon Dioxide, MgO
Transformation
Metamorphism
Yes
No
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Weathering
Yes
Yes
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
Yes
Yes
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Properties
Physical Properties
Hardness
3-4
3.5-4
Grain Size
Fine to Medium Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
Bluish Black
White
Porosity
Less Porous
Highly Porous
Luster
Grainy, Pearly and Vitreous
Shiny
Cleavage
Not Available
Slaty
Toughness
Not Available
1.5
Specific Gravity
Not Available
2.5-2.9
Transparency
Opaque
Opaque
Density
Not Available
2.8-2.9 g/cm3
Thermal Properties
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Impact Resistant, Pressure Resistant, Water Resistant
Reserves
Deposits in Eastern Continents
Asia
India, Russia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Africa
Ethiopia, Somalia, South Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Europe
Iceland
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Brazil
Brazil, Colombia, Guyana
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, New Zealand, Queensland
All about Adakite and Schist Properties
Know all about Adakite and Schist properties here. All properties of rocks are important as they define the type of rock and its application. Adakite belongs to Igneous Rocks while Schist belongs to Metamorphic Rocks.Texture of Adakite is Porphyritic whereas that of Schist is Foliated, Platy. Adakite appears Dull and Soft and Schist appears Layered and Shiny. The luster of Adakite is grainy, pearly and vitreous while that of Schist is shiny. Adakite is available in black, brown, light to dark grey colors whereas Schist is available in black, blue, brown, dark brown, green, grey, silver colors. The commercial uses of Adakite are commemorative tablets, pottery, used in aquariums and that of Schist are used in aquariums, writing slates.
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