Definition
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Edgar Bailey
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Blue, Bluish - Grey, Purple, Shades of Blue
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull and Banded
Dull and Soft
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
-
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Creating Artwork, Gemstone
Types
Metamorphic rock
Cataclastic rock
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Formation
Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.
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
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
-
Grain Size
Fine to Medium Grained
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
White to Grey
Light to dark brown
Porosity
Highly Porous
Less Porous
Specific Gravity
3-3.2
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
2.8-2.9 g/cm3
2.7-2.9 g/cm3
Resistance
Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Japan, Turkey
South Korea
Africa
Egypt, Ethiopia, South Africa
Western Africa
Europe
France, Greece, Iceland
Great Britain, Switzerland
Deposits in Western Continents
Deposits in Oceania Continent
Australia
New Zealand
Central Australia, Western Australia
Blueschist 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. Blueschist vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Blueschist and Properties of Pseudotachylite. Learn more about Blueschist vs Pseudotachylite in the next section. The interior uses of Blueschist include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Blueschist and Pseudotachylite, they have various applications in construction industry. The uses of Blueschist 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 Blueschist and Pseudotachylite
Here you can know more about Blueschist and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Blueschist and Pseudotachylite consists of mineral content and compound content. The mineral content of Blueschist includes Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz 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 Blueschist vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Blueschist is available in blue, bluish - grey, purple, shades of blue colors whereas, Pseudotachylite is available in black, brown, green, grey, pink, white colors. Appearance of Blueschist is Dull and Banded and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Blueschist vs Pseudotachylite. The hardness of Blueschist is 3.5-4 and that of Pseudotachylite is 7. The types of Blueschist are Metamorphic rock whereas types of Pseudotachylite are Cataclastic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Blueschist is white to grey while that of Pseudotachylite is light to dark brown. The specific heat capacity of Blueschist is 0.84 kJ/Kg K 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.Blueschist is impact resistant, pressure resistant whereas Pseudotachylite is heat resistant.