Definition
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
  
Hornblendite is a type of igneous plutonic rock consisting mainly of amphibole hornblende and is a type of Amphibolite rock
  
History
  
  
Origin
Western Australia, Minnesota
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
From its formation process
  
From German, Horn horn + blende
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Banded, Trellis
  
Banded, Foliated, Massive
  
Color
Red, Reddish Brown
  
Black, Brown, Green, Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Layered, Banded, Veined and Shiny
  
Foliated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes
  
Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Hotels, Interior Decoration, Kitchens
  
Exterior Uses
Paving Stone, Office Buildings
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing, Whetstones
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
  
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
As a touchstone, Cemetery Markers, Creating Artwork
  
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Types
Algoma-type , Lake Superior-type, Superior-type and Taconite
  
Hornblende Gabbro and Hornblende Peridotite
  
Features
Is one of the oldest rock
  
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
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
  
Fossils
Present
  
Absent
  
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.
  
Hornblendite 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.
  
Composition
  
  
Mineral Content
Hematite, Magnetite, Quartz
  
Amphibole, Calcite, Hornblade, Magnetite, Plagioclase, Wollastonite
  
Compound Content
Fe, Iron(III) Oxide, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
No
  
Types of Metamorphism
Not Applicable
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Wind Erosion
  
Chemical Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
5.5-6
  
6-7
  
Grain Size
Large and Coarse Grained
  
Medium to Coarse Grained
  
Fracture
Uneven, Splintery or Conchoidal
  
Irregular to Conchoidal
  
Streak
White
  
White to Grey
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Earthy
  
Vitreous to Dull
  
Cleavage
Imperfect
  
Irregular
  
Toughness
1.5
  
2.3
  
Specific Gravity
5.0-5.3
  
2.5
  
Transparency
Translucent to Opaque
  
Opaque
  
Density
Not Available
  
2.85-3.07 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
3.20 kJ/Kg K
  
1
Not Available
  
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
  
Russia, Turkey
  
Africa
Kenya, Morocco, South Africa, Tanzania
  
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
  
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
  
Germany, Greece, Iceland, Norway, Poland
  
Others
Greenland, Mid-Atlantic Ridge
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, Mexico, USA
  
Canada, USA
  
South America
Bolivia, Brazil
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, Queensland, South Australia, Western Australia
  
South Australia, Western Australia