Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
History
Origin
France
-
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
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
Family
Group
-
-
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
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Veined or Pebbled
Soft
Architecture
Interior Uses
-
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
-
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
-
Powder
Industry
Construction Industry
for Road Aggregate, 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
-
-
Antiquity Uses
-
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Electricity Generation
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
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Chalk Marl and Marl
Features
Generally rough to touch, 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
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Present
Formation
Coal formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Composition
Mineral Content
-
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Ca, NaCl, CaO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Physical Properties
Hardness
11
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
-
Streak
Black
White
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Dull
Compressive Strength
-5.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
1
Specific Gravity
1.1-1.42.3-2.4
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
800-801 g/cm32.49-2.50 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.26 kJ/Kg K0.90 kJ/Kg K
0.14
3.2
👆🏻
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
-
-
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, Victoria, Yorke Peninsula