Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
  
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
  
History
  
  
Origin
USA
  
Unknown
  
Discoverer
John Peter Salley
  
Unknown
  
Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
  
From German Grauwacke, from grau grey + wacke
  
Class
Sedimentary Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Amorphous, Glassy
  
Clastic
  
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
  
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Veined or Pebbled
  
Dull
  
Architecture
  
  
Interior Uses
Not Yet Used
  
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
  
Exterior Uses
Not Yet Used
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Not Yet Used
  
Curbing, Whetstones
  
Industry
  
  
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
  
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
  
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
  
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
  
Not Available
  
Features
Helps in production of Heat and Electricity, Used as fossil fuel
  
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
  
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
  
Fossils
Present
  
Present
  
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.
  
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
  
Composition
  
  
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
  
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
  
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
  
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Biological Weathering, Chemical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Coastal Erosion, Sea Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
1-1.5
  
6-7
  
Grain Size
Medium to Fine Coarse Grained
  
Angular and Fine
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Black
  
White
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Dull to Vitreous to Submetallic
  
Dull
  
Cleavage
Non-Existent
  
Perfect
  
Toughness
Not Available
  
2.6
  
Specific Gravity
1.1-1.4
  
2.2-2.8
  
Transparency
Opaque
  
Opaque
  
Density
1100-1400 g/cm3
  
2.6-2.61 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
1.32 kJ/Kg K
  
4
Not Available
  
Resistance
Heat Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
  
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
  
Namibia, Nigeria, South Africa
  
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
  
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
Others
Not Yet Found
  
Greenland
  
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
  
New South Wales, New Zealand
  
All about Coal and Greywacke Properties
Know all about Coal and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Coal and Greywacke belong to Sedimentary Rocks.Texture of Coal is Amorphous, Glassy whereas that of Greywacke is Clastic. Coal appears Veined or Pebbled and Greywacke appears Dull. The luster of Coal is dull to vitreous to submetallic while that of Greywacke is dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Greywacke is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow 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 Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.