Definition
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Origin
Germany
Western Australia, Minnesota
Discoverer
Christian Leopold von Buch
Unknown
Etymology
From Latin glaber bare, smooth, bald
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
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Phaneritic
Banded, Trellis
Color
Dark Grey to Black
Red, Reddish Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined and Shiny
Layered, Banded, Veined and Shiny
Interior Uses
Countertops, 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, Building houses or walls, 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
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
As a touchstone, Cemetery Markers, Creating Artwork
Types
Not Available
Algoma-type , Lake Superior-type, Superior-type and Taconite
Features
Smooth to touch
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
Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.
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
Augite, Olivine, Plagioclase, Pyroxene
Hematite, Magnetite, Quartz
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Fe, Iron(III) Oxide, Silicon Dioxide
Types of Metamorphism
Impact Metamorphism
Not Applicable
Types of Weathering
Chemical Weathering
Chemical Weathering
Types of Erosion
Coastal Erosion
Coastal Erosion, Wind Erosion
Grain Size
Coarse Grained
Large and Coarse Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Not Available
Earthy
Compressive Strength
Not Available
Cleavage
Not Available
Imperfect
Specific Gravity
2.86-2.87
5.0-5.3
Transparency
Opaque
Translucent to Opaque
Density
2.7-3.3 g/cm3
Not Available
Specific Heat Capacity
Not Available
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Germany, Greece, Italy, Scotland, Turkey
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Greenland
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil, Colombia, Venezuela
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New South Wales, Queensland, South Australia, Western Australia