Definition
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Origin
USA
Hawaii Islands
Discoverer
Edgar Bailey
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
From Greek pikros bitter + -ite, 19th century
Class
Metamorphic Rocks
Igneous 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
Texture
Foliated
Earthy, Rough
Color
Blue, Bluish - Grey, Purple, Shades of Blue
Black, Brown, Green, Grey, Pink, White, Yellow
Durability
Durable
Durable
Appearance
Dull and Banded
Rough and Shiny
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
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.
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Types
Metamorphic rock
Oceanite
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.
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.
Mineral Content
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
Biotite, Olivine, Plagioclase, Pyrrhotite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Al, CaO, Carbon Dioxide, Mg, MgO
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Uneven
Streak
White to Grey
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Dull
Subvitreous to Dull
Specific Gravity
3-3.2
2.75-2.92
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
1.5-2.5 g/cm3
Resistance
Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Japan, Turkey
India, Russia
Africa
Egypt, Ethiopia, South Africa
South Africa
Europe
France, Greece, Iceland
Iceland
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
All about Blueschist and Picrite Properties
Know all about Blueschist and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Blueschist belongs to Metamorphic Rocks while Picrite belongs to Igneous Rocks.Texture of Blueschist is Foliated whereas that of Picrite is Earthy, Rough. Blueschist appears Dull and Banded and Picrite appears Rough and Shiny. The luster of Blueschist is dull while that of Picrite is subvitreous to dull. Blueschist is available in blue, bluish - grey, purple, shades of blue colors whereas Picrite is available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Blueschist are cemetery markers, commemorative tablets, creating artwork, curling, tombstones and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).