Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
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 17th century, because of its greasy feel and use like a soap
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Polished
Color
Grey, White, Yellow
Black, Black to Grey, Green, Grey
Durability
Durable
Durable
Appearance
Soft
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Facing Stone, Garden Decoration
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
Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
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
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
Types
Chalk Marl and Marl
Metamorphic rock
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
-
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Compound Content
Ca, NaCl, CaO
CaO, Mg, MgO
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
-
Grain Size
Very fine-grained
Fine Grained
Porosity
Highly Porous
Less Porous
Specific Gravity
2.3-2.4
2.86
Transparency
Opaque
Opaque
Density
2.49-2.50 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Europe
England, France, Germany, Spain, United Kingdom
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Colombia
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
Central Australia, New Zealand, Queensland
Chalk vs Soapstone 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 Soapstone characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chalk and Properties of Soapstone. Learn more about Chalk vs Soapstone in the next section. The interior uses of Chalk include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Soapstone include Bathrooms, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Chalk and Soapstone, 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 Soapstone include Manufacture of magnesium and dolomite refractories.
More about Chalk and Soapstone
Here you can know more about Chalk and Soapstone. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chalk and Soapstone consists of mineral content and compound content. The mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand and mineral content of Soapstone includes Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz. You can also check out the list of all Sedimentary Rocks. When we have to compare Chalk vs Soapstone, the texture, color and appearance plays an important role in determining the type of rock. Chalk is available in grey, white, yellow colors whereas, Soapstone is available in black, black to grey, green, grey colors. Appearance of Chalk is Soft and that of Soapstone is Dull, Banded and Foilated. Properties of rock is another aspect for Chalk vs Soapstone. Hardness of Chalk and Soapstone is 1. The types of Chalk are Chalk Marl and Marl whereas types of Soapstone are Metamorphic rock. 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 Soapstone is black. The specific heat capacity of Chalk is 0.90 kJ/Kg K and that of Soapstone is 0.88 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 Soapstone is heat resistant, pressure resistant.