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