Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
John Peter Salley
Van Tooren
Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
From Greek tephra, ashes from Indo-European base, to burn
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Not Applicable
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Aphanitic to Porphyritic
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Appearance
Veined or Pebbled
Vesicular
Interior Uses
Not Yet Used
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Not Yet Used
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Not Yet Used
Curbing
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Sculpture
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Production of Lime, Soil Conditioner
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Not Available
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Host Rock for Lead
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Used
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.
Tephrite 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
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
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Uneven
Streak
Black
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Dull to Vitreous to Submetallic
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Non-Existent
Crenulation and Pervasive
Toughness
Not Available
2.4
Specific Gravity
1.1-1.4
2.86
Transparency
Opaque
Opaque
Density
1100-1400 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Not Yet Found
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Namibia, Uganda
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Germany, Hungary, Italy, Portugal, Spain
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Brazil, Chile, Colombia, Venezuela
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New Zealand, Western Australia
All about Coal and Tephrite Properties
Know all about Coal and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Tephrite belongs to Igneous Rocks.Texture of Coal is Amorphous, Glassy whereas that of Tephrite is Aphanitic to Porphyritic. Coal appears Veined or Pebbled and Tephrite appears Vesicular. The luster of Coal is dull to vitreous to submetallic while that of Tephrite is subvitreous to dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Tephrite is available in black, brown, colourless, green, grey, 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 Tephrite are production of lime, soil conditioner.