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
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
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
Durability
Durable
Durable
Appearance
Soft
Rough and Banded
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
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
-
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
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
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
Chalk Marl and Marl
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
Famous Monuments
-
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
Famous Sculptures
-
Ajanta Caves in Maharashtra, India, Elephanta Caves in Maharashtra, India
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.
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
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, Coastal Erosion
Grain Size
Very fine-grained
Fine Grained
Porosity
Highly Porous
Less Porous
Luster
Dull
Dull to Pearly
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
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
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Colombia
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
Chalk vs Limestone 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 Limestone characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chalk and Properties of Limestone. Learn more about Chalk vs Limestone in the next section. The interior uses of Chalk include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Limestone include Decorative aggregates and Interior decoration. Due to some exceptional properties of Chalk and Limestone, 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 Limestone include Cement manufacture, Cobblestones, For road aggregate, Production of glass and ceramics, Raw material for the manufacture of mortar, Roadstone, Source of calcium.
More about Chalk and Limestone
Here you can know more about Chalk and Limestone. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chalk and Limestone consists of mineral content and compound content. The mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand and mineral content of Limestone includes Calcite, Chert, Clay, Dolomite, Quartz, Sand, Silt. You can also check out the list of all Sedimentary Rocks. When we have to compare Chalk vs Limestone, the texture, color and appearance plays an important role in determining the type of rock. 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. Appearance of Chalk is Soft and that of Limestone is Rough and Banded. Properties of rock is another aspect for Chalk vs Limestone. The hardness of Chalk is 1 and that of Limestone is 3-4. The types of Chalk are Chalk Marl and Marl whereas types of Limestone are Chalk, Coquina, Fossiliferous Limestone, Lithographic Limestone, Oolitic Limestone, Travertine, Tufa. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chalk and Limestone is white. The specific heat capacity of Chalk is 0.90 kJ/Kg K and that of Limestone is 0.91 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 Limestone is pressure resistant.