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.
  
History
  
  
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
  
Family
  
  
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
  
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 and Soft
  
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
  
Other Architectural Uses
Whetstones
  
Curbing
  
Industry
  
  
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
  
Other Uses
  
  
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
  
  
Monuments
Used
  
Used
  
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
  
Fossils
Absent
  
Absent
  
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.
  
Composition
  
  
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
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
  
Physical Properties
  
  
Hardness
3-4
  
7
  
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
  
60.00 N/mm
2
  
25
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
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.92 kJ/Kg K
  
10
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
  
Adakite vs Pseudotachylite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Adakite vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Adakite and Properties of Pseudotachylite. Learn more about Adakite vs Pseudotachylite in the next section. The interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Adakite and Pseudotachylite, they have various applications in construction industry. The uses of Adakite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Adakite and Pseudotachylite
Here you can know more about Adakite and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Adakite and Pseudotachylite consists of mineral content and compound content. The mineral content of Adakite includes Olivine, Plagioclase, Pyroxene and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Igneous Rocks. When we have to compare Adakite vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Adakite is available in black, brown, light to dark grey colors whereas, Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Adakite is Dull and Soft and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Adakite vs Pseudotachylite. The hardness of Adakite is 3-4 and that of Pseudotachylite is 7. The types of Adakite are Not Available whereas types of Pseudotachylite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Adakite is bluish black while that of Pseudotachylite is light to dark brown. The specific heat capacity of Adakite is Not Available and that of Pseudotachylite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Adakite is heat resistant, pressure resistant, wear resistant whereas Pseudotachylite is heat resistant.