Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
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 English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
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 or Non-Clastic
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Grey, White, Yellow
Durability
Durable
Durable
Appearance
Veined or Pebbled
Soft
Interior Uses
Not Yet Used
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Not Yet Used
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Not Yet Used
Powder
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Not Available
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, 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
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.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
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
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Ca, NaCl, CaO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Not Available
Porosity
Less Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Dull
Cleavage
Non-Existent
Non-Existent
Toughness
Not Available
1
Specific Gravity
1.1-1.4
2.3-2.4
Transparency
Opaque
Opaque
Density
1100-1400 g/cm3
2.49-2.50 g/cm3
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
England, France, Germany, Spain, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Brazil, Chile, Colombia, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula
Coal vs Chalk Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Coal vs Chalk characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Coal and Properties of Chalk. Learn more about Coal vs Chalk in the next section. The interior uses of Coal include Not yet used whereas the interior uses of Chalk include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Coal and Chalk, they have various applications in construction industry. The uses of Coal in construction industry include Cement manufacture, For road aggregate, Making natural cement, Steel production and that of Chalk include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for manufacture of quicklime and slaked lime, Source of calcium.
More about Coal and Chalk
Here you can know more about Coal and Chalk. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Coal and Chalk consists of mineral content and compound content. The mineral content of Coal includes 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 and mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand. You can also check out the list of all Sedimentary Rocks. When we have to compare Coal vs Chalk, the texture, color and appearance plays an important role in determining the type of rock. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas, Chalk is available in grey, white, yellow colors. Appearance of Coal is Veined or Pebbled and that of Chalk is Soft. Properties of rock is another aspect for Coal vs Chalk. The hardness of Coal is 1-1.5 and that of Chalk is 1. The types of Coal are Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite whereas types of Chalk are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Coal is black while that of Chalk is white. The specific heat capacity of Coal is 1.32 kJ/Kg K and that of Chalk is 0.90 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Coal is heat resistant whereas Chalk is heat resistant.