Definition
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Origin
Western Australia, Minnesota
New Zealand
Discoverer
Johann Gottlob Lehmann
Ferdinand von Hochstetter
Etymology
From its formation process
From the name of Dun Mountain, New Zealand, + -ite1
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Banded, Trellis
Phaneritic
Color
Red, Reddish Brown
Dark Greenish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Rough and Shiny
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, 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 Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
As a touchstone, Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Types
Algoma-type , Lake Superior-type, Superior-type and Taconite
Dunite
Features
Is one of the oldest rock
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Archaeological Significance
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.
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Mineral Content
Hematite, Magnetite, Quartz
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Compound Content
Fe, Iron(III) Oxide, Silicon Dioxide
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Wind Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Large and Coarse Grained
Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Irregular
Porosity
Highly Porous
Less Porous
Specific Gravity
5.0-5.3
3-3.01
Transparency
Translucent to Opaque
Translucent to Opaque
Density
-9999 g/cm3
2.84-2.85 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Africa
Kenya, Morocco, South Africa, Tanzania
Morocco, South Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Bolivia, Brazil
Argentina, Brazil, Colombia, Ecuador, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New Zealand, Western Australia
Banded iron formation vs Dunite 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 Dunite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Banded iron formation and Properties of Dunite. Learn more about Banded iron formation vs Dunite in the next section. The interior uses of Banded iron formation include Decorative aggregates and Homes whereas the interior uses of Dunite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Banded iron formation and Dunite, 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 Dunite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar.
More about Banded iron formation and Dunite
Here you can know more about Banded iron formation and Dunite. 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 Dunite consists of mineral content and compound content. The mineral content of Banded iron formation includes Hematite, Magnetite, Quartz and mineral content of Dunite includes Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene. You can also check out the list of all Sedimentary Rocks. When we have to compare Banded iron formation vs Dunite, 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, Dunite is available in dark greenish - grey colors. Appearance of Banded iron formation is Layered, Banded, Veined and Shiny and that of Dunite is Rough and Shiny. Properties of rock is another aspect for Banded iron formation vs Dunite. The hardness of Banded iron formation is 5.5-6 and that of Dunite is 3.5-4. The types of Banded iron formation are Algoma-type , Lake Superior-type, Superior-type and Taconite whereas types of Dunite are Dunite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Banded iron formation and Dunite is white. The specific heat capacity of Banded iron formation is 3.20 kJ/Kg K and that of Dunite is 1.25 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 Dunite is heat resistant, pressure resistant, wear resistant.