Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
History
Origin
France
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
From French, Latin lignum wood + -ite1
From Adak, Aleutian Islands
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, Medium Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Porphyritic
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Light to Dark Grey
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, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
-
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
-
Whetstones
Industry
Construction Industry
for Road Aggregate, Steel Production
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
-
-
Antiquity Uses
-
Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Electricity Generation
Commemorative Tablets, Pottery, Used in aquariums
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Intermediate volcanic rock
Features
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
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.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
Composition
Mineral Content
-
Olivine, Plagioclase, Pyroxene
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, MgO, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Physical Properties
Hardness
13-4
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
Black
Bluish Black
Porosity
Highly Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
Grainy, Pearly and Vitreous
Compressive Strength
-200.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
-
Specific Gravity
1.1-1.4-9999
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
800-801 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.26 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
India, Russia
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Ethiopia, Somalia, South Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Iceland
Others
-
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Brazil, Chile, Colombia, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
-