Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
John Peter Salley
Unknown
Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Sedimentary Rocks
Metamorphic 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
Quench
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Veined or Pebbled
Dull and Soft
Interior Uses
-
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
-
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
-
Curbing
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Creating Artwork, Gemstone
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Cataclastic rock
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Host Rock for Lead
Archaeological Significance
Formation
Coal forms from the accumulation of plant debris in a swamp environment which is buried by sediments such as mud or sand and then compacted to form coal.
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
Analcime, Apatite, Barite, Calcite, Chalcopyrite, Chlorite, Chromite, Clausthalite, Clay Minerals, Crandallite Group, Dolomite, Feldspar, Galena, Gypsum, Marcasite, Muscovite or Illite, Pyrite, Quartz, Siderite, Sphalerite, Zircon
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
Black
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
Vitreous
Specific Gravity
1.1-1.4
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
1100-1400 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
South Korea
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Western Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Great Britain, Switzerland
Deposits in Western Continents
North America
Canada, Mexico, USA
-
South America
Brazil, Chile, Colombia, Venezuela
-
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
Central Australia, Western Australia
All about Coal and Pseudotachylite Properties
Know all about Coal and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Coal is Amorphous, Glassy whereas that of Pseudotachylite is Quench. Coal appears Veined or Pebbled and Pseudotachylite appears Dull and Soft. The luster of Coal is dull to vitreous to submetallic while that of Pseudotachylite is vitreous. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Coal are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry and that of Pseudotachylite are creating artwork, gemstone.