Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
  
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
  
History
  
  
Origin
USA
  
England
  
Discoverer
John Peter Salley
  
Unknown
  
Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
  
From Old French esclate, from esclat (French éclat)
  
Class
Sedimentary Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Medium Hardness 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
  
Foliated
  
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
  
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
No
  
Appearance
Veined or Pebbled
  
Dull
  
Architecture
  
  
Interior Uses
Not Yet Used
  
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
  
Exterior Uses
Not Yet Used
  
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Other Architectural Uses
Not Yet Used
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
  
As Dimension Stone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
  
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
  
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
  
Not Available
  
Features
Helps in production of Heat and Electricity, Used as fossil fuel
  
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Present
  
Absent
  
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.
  
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
  
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
  
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
  
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
1-1.5
  
3-4
  
Grain Size
Medium to Fine Coarse Grained
  
Very fine-grained
  
Fracture
Conchoidal
  
Splintery
  
Streak
Black
  
Light to dark brown
  
Porosity
Less Porous
  
Less Porous
  
Luster
Dull to Vitreous to Submetallic
  
Dull
  
Compressive Strength
Not Available
  
30.00 N/mm
2
  
30
Cleavage
Non-Existent
  
Slaty
  
Toughness
Not Available
  
1.2
  
Specific Gravity
1.1-1.4
  
2.65-2.8
  
Transparency
Opaque
  
Opaque
  
Density
1100-1400 g/cm3
  
2.6-2.8 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
1.32 kJ/Kg K
  
4
0.76 kJ/Kg K
  
17
Resistance
Heat Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
  
China, India, Turkey
  
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
  
Not Yet Found
  
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
  
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
  
Others
Not Yet Found
  
Arctic
  
Deposits in Western Continents
  
  
North America
Canada, Mexico, USA
  
USA
  
South America
Brazil, Chile, Colombia, Venezuela
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, Queensland, Victoria
  
Not Yet Found
  
All about Coal and Slate Properties
Know all about Coal and Slate properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Slate belongs to Metamorphic Rocks.Texture of Coal is Amorphous, Glassy whereas that of Slate is Foliated. Coal appears Veined or Pebbled and Slate appears Dull. The luster of Coal is dull to vitreous to submetallic while that of Slate is dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue 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 Slate are blackboards, commemorative tablets, laboratory bench tops, standard material for the bed of billiard table, standard material for the beds of pool and snooker table, tombstones, used in aquariums, writing slates.