Definition
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
History
Origin
-
Western Australia, Minnesota
Discoverer
Unknown
Johann Gottlob Lehmann
Etymology
From the mineral feldspathoid which is the main content of rock
From its formation process
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Earthy
Banded, Trellis
Color
Black, Brown, Green, Grey, Pink, White
Red, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull
Layered, Banded, Veined and Shiny
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Other Uses
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
As a touchstone, Cemetery Markers, Creating Artwork
Types
Igneous rock
Algoma-type , Lake Superior-type, Superior-type and Taconite
Features
Host Rock for Lead
Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Foidolites 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.
Composition
Mineral Content
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Hematite, Magnetite, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Fe, Iron(III) Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
-
Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Coastal Erosion, Wind Erosion
Physical Properties
Hardness
1.55.5-6
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Large and Coarse Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Streak
White
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Earthy
Compressive Strength
80.00 N/mm2220.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
-
1.5
Specific Gravity
2.865.0-5.3
0
8.4
👆🏻
Transparency
Translucent
Translucent to Opaque
Density
-9999 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.79 kJ/Kg K3.20 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
South Africa, Western Africa
Kenya, Morocco, South Africa, Tanzania
Europe
-
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
-
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
-
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, Queensland, South Australia, Western Australia