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
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Origin
Adak, Aleutian Islands
USA
Discoverer
Defant and Drummond
Unknown
Etymology
From Adak, Aleutian Islands
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Quench
Color
Black, Brown, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull and Soft
Dull and Soft
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
Other Architectural Uses
Whetstones
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
Creating Artwork, Gemstone
Types
Not Available
Not Available
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Not Yet Used
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. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Olivine, Plagioclase, Pyroxene
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Not Applicable
Grain Size
Fine to Medium Grained
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
Bluish Black
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Grainy, Pearly and Vitreous
Vitreous
Compressive Strength
Not Available
Cleavage
Not Available
Irregular
Toughness
Not Available
Not Available
Specific Gravity
Not Available
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
Not Available
2.7-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Russia
South Korea
Africa
Ethiopia, Somalia, South Africa
Western Africa
Europe
Iceland
Great Britain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Not Yet Found
South America
Brazil
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, Western Australia
All about Adakite and Pseudotachylite Properties
Know all about Adakite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Adakite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Adakite is Porphyritic whereas that of Pseudotachylite is Quench. Adakite appears Dull and Soft and Pseudotachylite appears Dull and Soft. The luster of Adakite is grainy, pearly and vitreous while that of Pseudotachylite is vitreous. Adakite is available in black, brown, light to dark grey colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Adakite are commemorative tablets, pottery, used in aquariums and that of Pseudotachylite are creating artwork, gemstone.