Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Discoverer
Unknown
Johann Gottlob Lehmann
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
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, Splintery
Color
Grey, White, Yellow
Black, Brown, Buff, Green, Grey, Red, Yellow
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, 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, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, 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
Creating Artwork, Pottery
Types
Chalk Marl and Marl
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Archaeological Significance
Famous Monuments
-
Jantar Mantar in India
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Compound Content
Ca, NaCl, CaO
Ca, Fe, Mg, Silicon Dioxide, Sodium
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, Glacier Erosion
Grain Size
Very fine-grained
Very fine-grained
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.3-2.4
2.2-2.8
Transparency
Opaque
Opaque
Density
2.49-2.50 g/cm3
2.4-2.8 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Bangladesh, China, India, Russia
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
England, France, Germany, Spain, United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
New South Wales, New Zealand, Queensland, Victoria, Western Australia
Chalk vs Shale 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 Shale characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chalk and Properties of Shale. Learn more about Chalk vs Shale in the next section. The interior uses of Chalk include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Shale include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Chalk and Shale, 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 Shale include Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar.
More about Chalk and Shale
Here you can know more about Chalk and Shale. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chalk and Shale consists of mineral content and compound content. The mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand and mineral content of Shale includes Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides. You can also check out the list of all Sedimentary Rocks. When we have to compare Chalk vs Shale, the texture, color and appearance plays an important role in determining the type of rock. Chalk is available in grey, white, yellow colors whereas, Shale is available in black, brown, buff, green, grey, red, yellow colors. Appearance of Chalk is Soft and that of Shale is Muddy. Properties of rock is another aspect for Chalk vs Shale. The hardness of Chalk is 1 and that of Shale is 3. The types of Chalk are Chalk Marl and Marl whereas types of Shale are Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chalk and Shale is white. The specific heat capacity of Chalk is 0.90 kJ/Kg K and that of Shale is 0.39 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 Shale is heat resistant, impact resistant.