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
Group
Not Applicable
Not Applicable
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
Not Yet Used
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Not Yet Used
Other Architectural Uses
Powder
Not Yet Used
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
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Not Yet Used
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
Not Available
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
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
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
Not Available
Compound Content
Ca, NaCl, CaO
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
Not Applicable
Not Applicable
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
Fracture
Not Available
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Dull
Dull to Vitreous to Submetallic
Cleavage
Non-Existent
Non-Existent
Toughness
1
Not Available
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
Others
Not Yet Found
Not Yet Found
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, Tonga, Victoria, Yorke Peninsula
New South Wales, Queensland, Victoria
Chalk vs Lignite 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. Chalk vs Lignite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chalk and Properties of Lignite. Learn more about Chalk vs Lignite in the next section. The interior uses of Chalk include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Lignite include Not yet used. Due to some exceptional properties of Chalk and Lignite, they have various applications in construction industry. The uses of Chalk in construction industry include 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 and that of Lignite include For road aggregate, Steel production.
More about Chalk and Lignite
Here you can know more about Chalk and Lignite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chalk and Lignite consists of mineral content and compound content. The mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand and mineral content of Lignite is not available. You can also check out the list of all Sedimentary Rocks. When we have to compare Chalk vs Lignite, the texture, color and appearance plays an important role in determining the type of rock. Chalk is available in grey, white, yellow colors whereas, Lignite is available in black, brown, dark brown, grey, light to dark grey colors. Appearance of Chalk is Soft and that of Lignite is Veined or Pebbled. Properties of rock is another aspect for Chalk vs Lignite. Hardness of Chalk and Lignite is 1. The types of Chalk are Not Available whereas types of Lignite are Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chalk is white while that of Lignite is black. The specific heat capacity of Chalk is 0.90 kJ/Kg K and that of Lignite is 1.26 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Chalk is heat resistant whereas Lignite is heat resistant.