Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
History
Origin
France
USA
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Quench
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Green, Grey, Pink, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Veined or Pebbled
Dull and Soft
Architecture
Interior Uses
-
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
-
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
-
Curbing
Industry
Construction Industry
for Road Aggregate, Steel Production
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
-
-
Antiquity Uses
-
Artifacts, Monuments
Other Uses
Commercial Uses
Electricity Generation
Creating Artwork, Gemstone
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Cataclastic rock
Features
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Composition
Mineral Content
-
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
-
Physical Properties
Hardness
17
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
Black
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
Vitreous
Compressive Strength
-60.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
-
Specific Gravity
1.1-1.42.46-2.86
0
8.4
👆🏻
Transparency
Opaque
Transparent to Translucent
Density
800-801 g/cm32.7-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.26 kJ/Kg K0.92 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
South Korea
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Western Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Great Britain, Switzerland
Others
-
-
Deposits in Western Continents
North America
Canada, Mexico, USA
-
South America
Brazil, Chile, Colombia, Venezuela
-
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
Central Australia, Western Australia