Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Discoverer
Unknown
Unknown
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
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy, Rough
Foliated, Platy
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Durability
Durable
Durable
Appearance
Rough and Shiny
Layered and Shiny
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration, Paving Stone
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, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Used in aquariums, Writing Slates
Types
Oceanite
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Features
Host Rock for Lead
Easily splits into thin plates, Smooth to touch
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.
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
CaO, Carbon Dioxide, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Shiny
Specific Gravity
2.75-2.92
2.5-2.9
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
India, Russia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Africa
South Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Europe
Iceland
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Brazil
Brazil, Colombia, Guyana
Deposits in Oceania Continent
Australia
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New South Wales, New Zealand, Queensland
All about Picrite and Schist Properties
Know all about Picrite and Schist properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Schist belongs to Metamorphic Rocks.Texture of Picrite is Earthy, Rough whereas that of Schist is Foliated, Platy. Picrite appears Rough and Shiny and Schist appears Layered and Shiny. The luster of Picrite is subvitreous to dull while that of Schist is shiny. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas Schist is available in black, blue, brown, dark brown, green, grey, silver 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 Schist are used in aquariums, writing slates.