Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Origin
France
Hawaii Islands
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
From Greek pikros bitter + -ite, 19th century
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Earthy, Rough
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Green, Grey, Pink, White, Yellow
Durability
Durable
Durable
Appearance
Veined or Pebbled
Rough and Shiny
Interior Uses
-
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
-
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
for Road Aggregate, Steel Production
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
Antiquity Uses
-
Artifacts, Monuments, Sculpture
Commercial Uses
Electricity Generation
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Oceanite
Features
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Host Rock for Lead
Archaeological Significance
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.
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
-
Biotite, Olivine, Plagioclase, Pyrrhotite
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Al, CaO, Carbon Dioxide, Mg, MgO
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Uneven
Streak
Black
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
Subvitreous to Dull
Specific Gravity
1.1-1.4
2.75-2.92
Transparency
Opaque
Opaque
Density
800-801 g/cm3
1.5-2.5 g/cm3
Resistance
Heat Resistant
Heat 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
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
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
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All about Lignite and Picrite Properties
Know all about Lignite and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Lignite belongs to Sedimentary Rocks while Picrite belongs to Igneous Rocks.Texture of Lignite is Amorphous, Glassy whereas that of Picrite is Earthy, Rough. Lignite appears Veined or Pebbled and Picrite appears Rough and Shiny. The luster of Lignite is dull to vitreous to submetallic while that of Picrite is subvitreous to dull. Lignite is available in black, brown, dark brown, grey, light to dark grey colors whereas Picrite is available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Lignite are electricity generation and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).