Definition
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
Origin
Western Australia, Minnesota
USA, Australia
Discoverer
Unknown
Tornebohm
Etymology
From its formation process
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Not Applicable
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Trellis
Earthy, Mud-rich, Rough
Color
Red, Reddish Brown
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Dull
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Not Applicable
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
As a touchstone, Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Algoma-type , Lake Superior-type, Superior-type and Taconite
Endoskarns
Features
Is one of the oldest rock
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Used
Formation
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Hematite, Magnetite, Quartz
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Fe, Iron(III) Oxide, Silicon Dioxide
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Chemical Weathering
Not Applicable
Types of Erosion
Coastal Erosion, Wind Erosion
Not Applicable
Grain Size
Large and Coarse Grained
Fine Grained
Fracture
Uneven, Splintery or Conchoidal
Irregular
Streak
White
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Earthy
Waxy and Dull
Specific Gravity
5.0-5.3
2.86
Transparency
Translucent to Opaque
Opaque
Density
Not Available
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Kenya, Morocco, South Africa, Tanzania
South Africa, Western Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
United Kingdom
Others
Greenland, Mid-Atlantic Ridge
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada
South America
Bolivia, Brazil
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
Central Australia, Western Australia
Banded iron formation vs Skarn 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. Banded iron formation vs Skarn characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Banded iron formation and Properties of Skarn. Learn more about Banded iron formation vs Skarn in the next section. The interior uses of Banded iron formation include Decorative aggregates and Homes whereas the interior uses of Skarn include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Banded iron formation and Skarn, they have various applications in construction industry. The uses of Banded iron formation in construction industry include As dimension stone, Used for flooring, stair treads, borders and window sills. and that of Skarn include As a flux in the production of steel and pig iron, As a sintering agent in steel industry to process iron ore, As dimension stone, Gold and silver production, Manufacture of magnesium and dolomite refractories.
More about Banded iron formation and Skarn
Here you can know more about Banded iron formation and Skarn. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Banded iron formation and Skarn consists of mineral content and compound content. The mineral content of Banded iron formation includes Hematite, Magnetite, Quartz and mineral content of Skarn includes Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite. You can also check out the list of all Sedimentary Rocks. When we have to compare Banded iron formation vs Skarn, the texture, color and appearance plays an important role in determining the type of rock. Banded iron formation is available in red, reddish brown colors whereas, Skarn is available in black, brown, colourless, green, grey, white colors. Appearance of Banded iron formation is Layered, Banded, Veined and Shiny and that of Skarn is Dull. Properties of rock is another aspect for Banded iron formation vs Skarn. The hardness of Banded iron formation is 5.5-6 and that of Skarn is 6.5. The types of Banded iron formation are Algoma-type , Lake Superior-type, Superior-type and Taconite whereas types of Skarn are Endoskarns. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Banded iron formation is white while that of Skarn is light to dark brown. The specific heat capacity of Banded iron formation is 3.20 kJ/Kg K and that of Skarn is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Banded iron formation is heat resistant, impact resistant, pressure resistant, wear resistant whereas Skarn is heat resistant.