Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Discoverer
Unknown
Unknown
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From French, Latin lignum wood + -ite1
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Amorphous, Glassy
Color
Grey, White, Yellow
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Soft
Veined or Pebbled
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
-
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
-
Other Architectural Uses
Powder
-
Construction Industry
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
for Road Aggregate, Steel Production
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
-
Commercial Uses
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
Electricity Generation
Types
Chalk Marl and Marl
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
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.
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
-
Compound Content
Ca, NaCl, CaO
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Porosity
Highly Porous
Highly Porous
Luster
Dull
Dull to Vitreous to Submetallic
Specific Gravity
2.3-2.4
1.1-1.4
Transparency
Opaque
Opaque
Density
2.49-2.50 g/cm3
800-801 g/cm3
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
England, France, Germany, Spain, United Kingdom
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Colombia
Brazil, Chile, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
New South Wales, Queensland, Victoria
All about Chalk and Lignite Properties
Know all about Chalk and Lignite properties here. All properties of rocks are important as they define the type of rock and its application. Chalk and Lignite belong to Sedimentary Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Lignite is Amorphous, Glassy. Chalk appears Soft and Lignite appears Veined or Pebbled. The luster of Chalk is dull while that of Lignite is dull to vitreous to submetallic. Chalk is available in grey, white, yellow colors whereas Lignite is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Chalk are 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 and that of Lignite are electricity generation.