Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
History
Origin
-
Discoverer
Unknown
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Family
Group
-
Other Categories
Fine Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Color
Grey, White, Yellow
Maintenance
Less
Durability
Durable
Water Resistant
✔
✘
58% - Sedimentary Rocks Rocks
Scratch Resistant
✔
✘
61% - Sedimentary Rocks Rocks
Stain Resistant
✔
✘
42% - Sedimentary Rocks Rocks
Wind Resistant
✔
✘
36% - Sedimentary Rocks Rocks
Acid Resistant
✔
✘
19% - Sedimentary Rocks Rocks
Appearance
Soft
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Powder
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
Medical Industry
-
Antiquity Uses
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
Types
Chalk Marl and Marl
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Monuments
-
Famous Monuments
-
Sculpture
-
Famous Sculptures
-
Pictographs
-
Petroglyphs
-
Figurines
-
Fossils
Present
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Composition
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Ca, NaCl, CaO
Transformation
Metamorphism
✔
✘
17% - Sedimentary Rocks Rocks
Types of Metamorphism
-
Weathering
✔
✘
78% - Sedimentary Rocks Rocks have it !
Types of Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
86% - Sedimentary Rocks Rocks have it !
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Physical Properties
Hardness
1
1
7
👆🏻
Grain Size
Very fine-grained
Fracture
-
Streak
White
Porosity
Highly Porous
Luster
Dull
Compressive Strength
5.00 N/mm2
Rank: 47 (Overall)
0.15
450
👆🏻
Cleavage
-
Toughness
1
Specific Gravity
2.3-2.4
0
8.4
👆🏻
Transparency
Opaque
Density
2.49-2.50 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.90 kJ/Kg K
Rank: 12 (Overall)
0.14
3.2
👆🏻
Resistance
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
Europe
England, France, Germany, Spain, United Kingdom
Others
-
Deposits in Western Continents
North America
Canada, USA
South America
Colombia
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula