Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Origin
-
Western Australia, Minnesota
Discoverer
Unknown
Johann Gottlob Lehmann
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From its formation process
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Banded, Rough
Banded, Trellis
Color
Black, Brown, Green, Grey, Red, White
Red, Reddish Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Glassy or Pearly
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
As a touchstone, Cemetery Markers, Creating Artwork
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Algoma-type , Lake Superior-type, Superior-type and Taconite
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Is one of the oldest rock
Archaeological Significance
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.
The banded iron layers are formed in sea water when oxygen is released by photosynthetic cyano-bacteria. The oxygen then combines with dissolved iron in ocean to form insoluble iron oxides, which precipitated out, forming a thin layer of banded iron formation on ocean floor.
Mineral Content
Quartz, Silicon
Hematite, Magnetite, Quartz
Compound Content
Silicon Dioxide
Fe, Iron(III) Oxide, Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
-
Chemical Weathering
Types of Erosion
Chemical Erosion
Coastal Erosion, Wind Erosion
Grain Size
Very fine-grained
Large and Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Waxy and Dull
Earthy
Specific Gravity
2.5-2.8
5.0-5.3
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.7 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Kenya, Morocco, South Africa, Tanzania
Kenya, Morocco, South Africa, Tanzania
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Greenland, Mid-Atlantic Ridge
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Mexico, USA
South America
Bolivia, Brazil
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New South Wales, Queensland, South Australia, Western Australia
Chert vs Banded iron formation 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. Chert vs Banded iron formation characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chert and Properties of Banded iron formation. Learn more about Chert vs Banded iron formation in the next section. The interior uses of Chert include Decorative aggregates and Homes whereas the interior uses of Banded iron formation include Decorative aggregates and Homes. Due to some exceptional properties of Chert and Banded iron formation, they have various applications in construction industry. The uses of Chert in construction industry include Arrowheads, Construction aggregate, Cutting tool, Spear points and that of Banded iron formation include As dimension stone, Used for flooring, stair treads, borders and window sills..
More about Chert and Banded iron formation
Here you can know more about Chert and Banded iron formation. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chert and Banded iron formation consists of mineral content and compound content. The mineral content of Chert includes Quartz, Silicon and mineral content of Banded iron formation includes Hematite, Magnetite, Quartz. You can also check out the list of all Sedimentary Rocks. When we have to compare Chert vs Banded iron formation, the texture, color and appearance plays an important role in determining the type of rock. Chert is available in black, brown, green, grey, red, white colors whereas, Banded iron formation is available in red, reddish brown colors. Appearance of Chert is Glassy or Pearly and that of Banded iron formation is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Chert vs Banded iron formation. The hardness of Chert is 6.5-7 and that of Banded iron formation is 5.5-6. The types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter whereas types of Banded iron formation are Algoma-type , Lake Superior-type, Superior-type and Taconite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chert and Banded iron formation is white. The specific heat capacity of Chert is 0.74 kJ/Kg K and that of Banded iron formation is 3.20 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Chert is heat resistant, impact resistant, pressure resistant, wear resistant whereas Banded iron formation is heat resistant, impact resistant, pressure resistant, wear resistant.