Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Origin
Brazil
Western Australia, Minnesota
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From its formation process
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Aphanitic
Banded, Trellis
Color
Black, Brown, Colourless, Green, Grey, White
Red, Reddish Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
As a touchstone, Cemetery Markers, Creating Artwork
Types
Peralkaline Nephelinite
Algoma-type , Lake Superior-type, Superior-type and Taconite
Features
Host Rock for Lead
Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Not Yet Used
Formation
Nephelinite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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
Clinopyroxene, Nepheline, Plagioclase
Hematite, Magnetite, Quartz
Compound Content
Ca, CaO, Carbon, Cl, MgO
Fe, Iron(III) Oxide, Silicon Dioxide
Types of Metamorphism
Contact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Wind Erosion
Grain Size
Fine Grained
Large and Coarse Grained
Fracture
Flat
Uneven, Splintery or Conchoidal
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
Earthy
Compressive Strength
Not Available
Cleavage
Imperfect
Imperfect
Specific Gravity
2.4-2.9
5.0-5.3
Transparency
Opaque
Translucent to Opaque
Density
2.5-3 g/cm3
Not Available
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Japan
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Rwanda, Tanzania
Kenya, Morocco, South Africa, Tanzania
Europe
Not Yet Found
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Hawaii Islands
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Colombia
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, Queensland, South Australia, Western Australia
All about Nephelinite and Banded iron formation Properties
Know all about Nephelinite and Banded iron formation properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Banded iron formation belongs to Sedimentary Rocks.Texture of Nephelinite is Aphanitic whereas that of Banded iron formation is Banded, Trellis. Nephelinite appears Skeletal and Banded iron formation appears Layered, Banded, Veined and Shiny. The luster of Nephelinite is vitreous to metallic while that of Banded iron formation is earthy. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Banded iron formation is available in red, reddish brown colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Banded iron formation are as a touchstone, cemetery markers, creating artwork.