Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Origin
Pennsylvania, U.S.
Hawaii Islands
Discoverer
Unknown
Unknown
Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal
From Greek pikros bitter + -ite, 19th century
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Earthy, Rough
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Green, Grey, Pink, White, Yellow
Durability
Durable
Durable
Appearance
Veined or Pebbled
Rough and Shiny
Interior Uses
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Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
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As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
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Curbing
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
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.
Medical Industry
In Chemical and Pharmaceutical Industry, Manufacture of Aspirins
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Antiquity Uses
-
Artifacts, Monuments, Sculpture
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Types
Semi-anthracite and Meta-anthracite
Oceanite
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Host Rock for Lead
Archaeological Significance
Formation
Anthracite forms from the accumulation of plant debris in a swamp environment. When plant debris dies and falls into the swamp, the standing water of the swamp protects it from decay.
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
Calcite, Clay, Clay Minerals
Biotite, Olivine, Plagioclase, Pyrrhotite
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Al, CaO, Carbon Dioxide, Mg, MgO
Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
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Biological Weathering
Types of Erosion
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Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Uneven
Streak
Black
White, Greenish White or Grey
Porosity
Less Porous
Less Porous
Luster
Shiny
Subvitreous to Dull
Specific Gravity
1.1-1.4
2.75-2.92
Transparency
Opaque
Opaque
Density
1.25-2.5 g/cm3
1.5-2.5 g/cm3
Resistance
Heat Resistant, Water Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
India, Russia
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
South Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Iceland
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Brazil, Chile, Colombia, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
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All about Anthracite and Picrite Properties
Know all about Anthracite and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Anthracite belongs to Metamorphic Rocks while Picrite belongs to Igneous Rocks.Texture of Anthracite is Amorphous, Glassy whereas that of Picrite is Earthy, Rough. Anthracite appears Veined or Pebbled and Picrite appears Rough and Shiny. The luster of Anthracite is shiny while that of Picrite is subvitreous to dull. Anthracite is available in black, brown, dark brown, grey, light to dark grey colors whereas Picrite is available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Anthracite are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).