Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
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
Origin
USA
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From Adak, Aleutian Islands
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Quench
Porphyritic
Color
Black, Brown, Green, Grey, Pink, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull and Soft
Dull and Soft
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments
Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone
Commemorative Tablets, Pottery, Used in aquariums
Types
Cataclastic rock
Intermediate volcanic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Archaeological Significance
Formation
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.
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.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Olivine, Plagioclase, Pyroxene
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
-
Chemical Weathering, Mechanical Weathering
Types of Erosion
-
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Very fine-grained
Fine to Medium Grained
Fracture
Uneven
Conchoidal
Streak
Light to dark brown
Bluish Black
Porosity
Less Porous
Less Porous
Luster
Vitreous
Grainy, Pearly and Vitreous
Specific Gravity
2.46-2.86
-9999
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
-9999 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
South Korea
India, Russia
Africa
Western Africa
Ethiopia, Somalia, South Africa
Europe
Great Britain, Switzerland
Iceland
Deposits in Western Continents
North America
-
Canada, USA
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-
Pseudotachylite vs Adakite 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. Pseudotachylite vs Adakite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pseudotachylite and Properties of Adakite. Learn more about Pseudotachylite vs Adakite in the next section. The interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens. Due to some exceptional properties of Pseudotachylite and Adakite, they have various applications in construction industry. The uses of Pseudotachylite in construction industry include As dimension stone, Cement manufacture, For road aggregate, Making natural cement and that of Adakite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Pseudotachylite and Adakite
Here you can know more about Pseudotachylite and Adakite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pseudotachylite and Adakite consists of mineral content and compound content. The mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides and mineral content of Adakite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Pseudotachylite vs Adakite, the texture, color and appearance plays an important role in determining the type of rock. Pseudotachylite is available in black, brown, green, grey, pink, white colors whereas, Adakite is available in black, brown, light to dark grey colors. Appearance of Pseudotachylite is Dull and Soft and that of Adakite is Dull and Soft. Properties of rock is another aspect for Pseudotachylite vs Adakite. The hardness of Pseudotachylite is 7 and that of Adakite is 3-4. The types of Pseudotachylite are Cataclastic rock whereas types of Adakite are Intermediate volcanic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Pseudotachylite is light to dark brown while that of Adakite is bluish black. The specific heat capacity of Pseudotachylite is 0.92 kJ/Kg K and that of Adakite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Pseudotachylite is heat resistant whereas Adakite is heat resistant, pressure resistant, wear resistant.