Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
A sedimentary rock, deposit of a submarine turbidity currents and are composed of layered particles
History
Origin
-
European Foreland Basins
Discoverer
Unknown
Arnold H. Bouma
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From Medieval Latin turbiditas, from Latin turbidus (turbid). Turbidity current is from 1939
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Mud-rich, Sandy
Color
Grey, White, Yellow
Black, Brown, Green, Grey, Pink
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Soft
Dull and Banded
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Bathrooms, Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
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
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
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
Cemetery Markers, Creating Artwork
Types
Chalk Marl and Marl
Sedimentary rock
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
High silica content, Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
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.
Turbidite is a type of sedimentary rock formed when a river carries or transports pieces of broken rock as it flows. These particles then settle down and are subjected to high temperature and pressures hence forming Turbidite.
Composition
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Coesite, Quartz, Sand
Compound Content
Ca, NaCl, CaO
CaO, Carbon Dioxide, MgO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
13
1
7
👆🏻
Grain Size
Very fine-grained
Fine to Coarse Grained
Fracture
-
Splintery
Streak
White
White, Greenish White or Grey
Porosity
Highly Porous
Very Less Porous
Luster
Dull
Metallic
Compressive Strength
5.00 N/mm2200.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Disjunctive
Toughness
1
2.4
Specific Gravity
2.3-2.42.46-2.73
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.49-2.50 g/cm31.6-2.5 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.90 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
-
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Western Africa
Europe
England, France, Germany, Spain, United Kingdom
Austria, Belarus, Romania, Switzerland, United Kingdom
Others
-
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Brazil, Colombia
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
New Zealand, Western Australia