Definition
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Pyroxenite is a dark, greenish, granular intrusive igneous rock consisting mainly of pyroxenes and olivine
Origin
Western Australia, Minnesota
-
Discoverer
Johann Gottlob Lehmann
Unknown
Etymology
From its formation process
From pyro- fire + Greek xenos stranger as the mineral group was new to igneous rocks
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Banded, Trellis
Clastic, Granular, Phaneritic, Porphyritic
Color
Red, Reddish Brown
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes
Countertops, Decorative Aggregates, Interior Decoration, Kitchens
Exterior Uses
Paving Stone, Office Buildings
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
As a touchstone, Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Algoma-type , Lake Superior-type, Superior-type and Taconite
Clinopyroxenites, Orthopyroxenites and Websterites
Features
Is one of the oldest rock
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.
Pyroxenites are ultramafic igneous rocks which are made up of minerals of the pyroxene group, such as augite and diopside, hypersthene, bronzite or enstatite.
Mineral Content
Hematite, Magnetite, Quartz
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
Compound Content
Fe, Iron(III) Oxide, Silicon Dioxide
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
-
Burial Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Large and Coarse Grained
Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Uneven
Streak
White
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Earthy
Dull to Vitreous to Submetallic
Specific Gravity
5.0-5.3
3.2-3.5
Transparency
Translucent to Opaque
Opaque
Density
-9999 g/cm3
3.1-3.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
India, Russia
Africa
Kenya, Morocco, South Africa, Tanzania
South Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Others
Greenland, Mid-Atlantic Ridge
Greenland
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Bolivia, Brazil
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New Zealand, Queensland
Banded iron formation vs Pyroxenite 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 Pyroxenite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Banded iron formation and Properties of Pyroxenite. Learn more about Banded iron formation vs Pyroxenite in the next section. The interior uses of Banded iron formation include Decorative aggregates and Homes whereas the interior uses of Pyroxenite include Countertops, Decorative aggregates, Interior decoration and Kitchens. Due to some exceptional properties of Banded iron formation and Pyroxenite, 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 Pyroxenite include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Banded iron formation and Pyroxenite
Here you can know more about Banded iron formation and Pyroxenite. 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 Pyroxenite consists of mineral content and compound content. The mineral content of Banded iron formation includes Hematite, Magnetite, Quartz and mineral content of Pyroxenite includes Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene. You can also check out the list of all Sedimentary Rocks. When we have to compare Banded iron formation vs Pyroxenite, 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, Pyroxenite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. Appearance of Banded iron formation is Layered, Banded, Veined and Shiny and that of Pyroxenite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Banded iron formation vs Pyroxenite. The hardness of Banded iron formation is 5.5-6 and that of Pyroxenite is 7. The types of Banded iron formation are Algoma-type , Lake Superior-type, Superior-type and Taconite whereas types of Pyroxenite are Clinopyroxenites, Orthopyroxenites and Websterites. 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 Pyroxenite is white, greenish white or grey. The specific heat capacity of Banded iron formation is 3.20 kJ/Kg K and that of Pyroxenite is 0.84 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 Pyroxenite is impact resistant, pressure resistant, wear resistant.