Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
From Latin varius, speckled, variegated
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
Opaque Rock
Texture
Amorphous, Glassy
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Veined or Pebbled
Dull and Soft
Interior Uses
-
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
-
Garden Decoration, Office Buildings
Other Architectural Uses
-
Curbing
Construction Industry
for Road Aggregate, Steel Production
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
-
Artifacts, Monuments, Sculpture
Commercial Uses
Electricity Generation
Cemetery Markers, Creating Artwork
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Metamorphic 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, Very fine grained rock
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.
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
Mineral Content
-
Olivine, Plagioclase, Pyroxene
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
-
Grain Size
Medium to Fine Coarse Grained
-
Fracture
Conchoidal
Conchoidal
Streak
Black
White to Grey
Porosity
Highly Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
-
Specific Gravity
1.1-1.4
2.8-3
Transparency
Opaque
Opaque
Density
800-801 g/cm3
2.9-3.1 g/cm3
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
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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Lignite vs Variolite 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. Lignite vs Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Lignite and Properties of Variolite. Learn more about Lignite vs Variolite in the next section. The interior uses of Lignite include whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Lignite and Variolite, they have various applications in construction industry. The uses of Lignite in construction industry include For road aggregate, Steel production and that of Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Lignite and Variolite
Here you can know more about Lignite and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Lignite and Variolite consists of mineral content and compound content. The mineral content of Lignite includes and mineral content of Variolite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Sedimentary Rocks. When we have to compare Lignite vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Lignite is available in black, brown, dark brown, grey, light to dark grey colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Lignite is Veined or Pebbled and that of Variolite is Dull and Soft. Properties of rock is another aspect for Lignite vs Variolite. The hardness of Lignite is 1 and that of Variolite is 6. The types of Lignite are Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite whereas types of Variolite are Metamorphic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Lignite is black while that of Variolite is white to grey. The specific heat capacity of Lignite is 1.26 kJ/Kg K and that of Variolite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Lignite is heat resistant whereas Variolite is heat resistant, pressure resistant, wear resistant.