Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Origin
Hawaii Islands
USA
Discoverer
Unknown
Edgar Bailey
Etymology
From Greek pikros bitter + -ite, 19th century
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic 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
Earthy, Rough
Foliated
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Blue, Bluish - Grey, Purple, Shades of Blue
Durability
Durable
Durable
Appearance
Rough and Shiny
Dull and Banded
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
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Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Types
Oceanite
Metamorphic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Formation
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering
Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine to Medium Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Specific Gravity
2.75-2.92
3-3.2
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
Japan, Turkey
Africa
South Africa
Egypt, Ethiopia, South Africa
Europe
Iceland
France, Greece, Iceland
Deposits in Western Continents
North America
Canada, USA
USA
Deposits in Oceania Continent
All about Picrite and Blueschist Properties
Know all about Picrite and Blueschist properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Blueschist belongs to Metamorphic Rocks.Texture of Picrite is Earthy, Rough whereas that of Blueschist is Foliated. Picrite appears Rough and Shiny and Blueschist appears Dull and Banded. The luster of Picrite is subvitreous to dull while that of Blueschist is dull. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas Blueschist is available in blue, bluish - grey, purple, shades of blue colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Blueschist are cemetery markers, commemorative tablets, creating artwork, curling, tombstones.