Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
  
Limestone is a sedimentary rock composed mostly of calcite and aragonite, which are different crystal forms of calcium carbonate
  
History
  
  
Origin
Unknown
  
New Zealand
  
Discoverer
Unknown
  
Belsazar Hacquet
  
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
  
From lime and stone in late 14th Century
  
Class
Sedimentary Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Clastic or Non-Clastic
  
Clastic or Non-Clastic
  
Color
Grey, White, Yellow
  
Beige, Black, Blue, Brown, Cream, Gold, Green, Grey, Light Green, Light Grey, Linen, Pink, Red, Rust, Silver, White, Yellow
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
No
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
No
  
Appearance
Soft
  
Rough and Banded
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Powder
  
Curbing
  
Industry
  
  
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
  
Cement Manufacture, Cobblestones, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar, Roadstone, Source of calcium
  
Medical Industry
Not Yet Used
  
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
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
  
Animal feed filler, As a Feed Additive for Livestock, Paper Industry, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Used in aquariums, Whiting material in toothpaste, paint and paper
  
Types
Not Available
  
Chalk, Coquina, Fossiliferous Limestone, Lithographic Limestone, Oolitic Limestone, Travertine, Tufa
  
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
  
Host Rock for Lead, Stalactites and stalagmites are formed from this rock, Zinc and Copper Deposits
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Acropolis of Athens in Greece, Agia Sophia in Istanbul, Turkey, Al Aqsa Mosque in Jerusalem, Angkor Wat in Cambodia, Big Ben in London, Charminar in Hyderabad, India, Chhatrapati Shivaji Terminus in Maharashtra, India, Chichen Itza in Mexico, Empire State Building in New York, Khajuraho Temples, India, Kremlin in Moscow, Louvre in Paris, France, Neuschwanstein in Bavaria, Potala Palace in Lahasa, Tibet, Wailing Wall in Jerusalem
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Ajanta Caves in Maharashtra, India, Elephanta Caves in Maharashtra, India
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Present
  
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
  
Limestone is a sedimentary rock which is mainly made up of calcium carbonate.
  
Composition
  
  
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
  
Calcite, Chert, Clay, Dolomite, Quartz, Sand, Silt
  
Compound Content
Ca, NaCl, CaO
  
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, MgO
  
Transformation
  
  
Metamorphism
No
  
No
  
Types of Metamorphism
Not Applicable
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
  
Chemical Erosion, Coastal Erosion
  
Physical Properties
  
  
Hardness
1
  
3-4
  
Grain Size
Very fine-grained
  
Fine Grained
  
Fracture
Not Available
  
Splintery
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Dull to Pearly
  
Compressive Strength
Not Available
  
115.00 N/mm
2
  
18
Cleavage
Non-Existent
  
Non-Existent
  
Toughness
1
  
1
  
Specific Gravity
2.3-2.4
  
2.3-2.7
  
Transparency
Opaque
  
Opaque
  
Density
2.49-2.50 g/cm3
  
2.3-2.7 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.90 kJ/Kg K
  
12
0.91 kJ/Kg K
  
11
Resistance
Heat Resistant
  
Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
  
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
  
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
  
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
  
Europe
England, France, Germany, Spain, United Kingdom
  
United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Colombia
  
Colombia
  
Deposits in Oceania Continent
  
  
Australia
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula
  
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula
  
All about Chalk and Limestone Properties
Know all about Chalk and Limestone properties here. All properties of rocks are important as they define the type of rock and its application. Chalk and Limestone belong to Sedimentary Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Limestone is Clastic or Non-Clastic. Chalk appears Soft and Limestone appears Rough and Banded. The luster of Chalk is dull while that of Limestone is dull to pearly. Chalk is available in grey, white, yellow colors whereas Limestone is available in beige, black, blue, brown, cream, gold, green, grey, light green, light grey, linen, pink, red, rust, silver, white, yellow 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 Limestone are animal feed filler, as a feed additive for livestock, paper industry, raw material for manufacture of quicklime, slaked lime, soil conditioner, used in aquariums, whiting material in toothpaste, paint and paper.