Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
History
Origin
USA
-
Discoverer
John Peter Salley
Unknown
Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Vesicular
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Dark Grey to Black, Red
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Veined or Pebbled
Glassy and Vesicular
Architecture
Interior Uses
-
Decorative Aggregates, Interior Decoration
Exterior Uses
-
Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Industry
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Basaltic Scoria and Andesitic Scoria
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
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.
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
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, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Ca, NaCl
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Glacier Erosion
Physical Properties
Hardness
1-1.55-6
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
Black
White
Porosity
Less Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Subvitreous to Dull
Compressive Strength
-70.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
-
2.1
Specific Gravity
1.1-1.4-9999
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
1100-1400 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.32 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
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
Afghanistan, Indonesia, Japan, Russia
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Ethiopia, Kenya, Tanzania
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
-
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
South America
Brazil, Chile, Colombia, Venezuela
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New Zealand, Western Australia