Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
  
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
  
History
  
  
Origin
Unknown
  
USA
  
Discoverer
Unknown
  
Unknown
  
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
  
From 17th century, because of its greasy feel and use like a soap
  
Class
Sedimentary Rocks
  
Metamorphic 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
Banded, Rough
  
Polished
  
Color
Black, Brown, Green, Grey, Red, White
  
Black, Black to Grey, Green, Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Glassy or Pearly
  
Dull, Banded and Foilated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes
  
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
  
As Facing Stone, Garden Decoration
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
  
Manufacture of Magnesium and Dolomite Refractories
  
Medical Industry
Not Yet Used
  
Taken as a Supplement for Calcium or Magnesium
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts, Jewellery, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
  
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
  
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
  
Not Available
  
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Present
  
Absent
  
Formation
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
  
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.
  
Composition
  
  
Mineral Content
Quartz, Silicon
  
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
  
Compound Content
Silicon Dioxide
  
CaO, Mg, MgO
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
No
  
No
  
Types of Weathering
Not Applicable
  
Not Applicable
  
Erosion
Yes
  
No
  
Types of Erosion
Chemical Erosion
  
Not Applicable
  
Physical Properties
  
  
Hardness
6.5-7
  
1
  
Grain Size
Very fine-grained
  
Fine Grained
  
Fracture
Uneven, Splintery or Conchoidal
  
Conchoidal
  
Streak
White
  
Black
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Waxy and Dull
  
Greasy
  
Compressive Strength
450.00 N/mm2
  
1
225.00 N/mm2
  
7
Cleavage
Non-Existent
  
Perfect
  
Toughness
1.5
  
1
  
Specific Gravity
2.5-2.8
  
2.86
  
Transparency
Translucent to Opaque
  
Opaque
  
Density
2.7 g/cm3
  
2.8-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.74 kJ/Kg K
  
19
0.88 kJ/Kg K
  
13
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
  
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
  
Africa
Kenya, Morocco, South Africa, Tanzania
  
Egypt, Ethiopia, Ghana, South Africa, Western Africa
  
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
  
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
  
Others
Greenland, Mid-Atlantic Ridge
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, Mexico, USA
  
Canada, USA
  
South America
Bolivia, Brazil
  
Colombia
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, Queensland, South Australia, Western Australia
  
Central Australia, New Zealand, Queensland
  
All about Chert and Soapstone Properties
Know all about Chert and Soapstone properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Soapstone belongs to Metamorphic Rocks.Texture of Chert is Banded, Rough whereas that of Soapstone is Polished. Chert appears Glassy or Pearly and Soapstone appears Dull, Banded and Foilated. The luster of Chert is waxy and dull while that of Soapstone is greasy. Chert is available in black, brown, green, grey, red, white colors whereas Soapstone is available in black, black to grey, green, grey colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Soapstone are cemetery markers, creating artwork, gemstone, jewelry, manufacture of soap, solvents, dyes, plastics and fibres, production of lime, source of magnesia (mgo).