Definition
Siltstone can be defined as a fine-grained sedimentary rock which mainly consists of consolidated silt
  
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
  
History
  
  
Discoverer
Unknown
  
Unknown
  
Etymology
From English word silt and stone and from Proto-Indo-European root sal and stainaz
  
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
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Clastic
  
Clastic or Non-Clastic
  
Color
Brown, Red, Reddish Brown
  
Grey, White, Yellow
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Rough
  
Soft
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
  
Other Architectural Uses
Curbing
  
Powder
  
Industry
  
  
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
  
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
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Raw material for the manufacture of mortar, Soil Conditioner
  
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
Not Available
  
Not Available
  
Features
Available in Lots of Colors and Patterns, Easily splits into thin plates, Generally rough to touch, High silica content, Very fine grained rock
  
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Present
  
Formation
Siltstone is a type of sedimentary rock which is formed from fine rock particles. As the particles of eroded rock travel along with water, the edges of the rock are worn-out by water into a rounded shape.
  
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, Feldspar, Micas, Quartz, Sand, Silica, Silt
  
Calcite, Clay, Clay Minerals, Quartz, Sand
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
  
Ca, NaCl, CaO
  
Transformation
  
  
Metamorphism
No
  
No
  
Types of Metamorphism
Not Applicable
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Chemical Erosion, Coastal Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6-7
  
1
  
Grain Size
Fine Grained
  
Very fine-grained
  
Fracture
Conchoidal
  
Not Available
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Highly Porous
  
Luster
Dull
  
Dull
  
Cleavage
Not Available
  
Non-Existent
  
Toughness
2.6
  
1
  
Specific Gravity
2.54-2.73
  
2.3-2.4
  
Transparency
Opaque
  
Opaque
  
Density
2.6-2.7 g/cm3
  
2.49-2.50 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.90 kJ/Kg K
  
12
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Water Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
  
Africa
Namibia, Nigeria, South Africa
  
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
  
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
England, France, Germany, Spain, United Kingdom
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Colombia
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand
  
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula