Definition
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
History
Origin
Adak, Aleutian Islands
Western Australia, Minnesota
Discoverer
Defant and Drummond
Johann Gottlob Lehmann
Etymology
From Adak, Aleutian Islands
From its formation process
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Porphyritic
Banded, Trellis
Color
Black, Brown, Light to Dark Grey
Red, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull and Soft
Layered, Banded, Veined and Shiny
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
Paving Stone, Office Buildings
Other Architectural Uses
Whetstones
Curbing, Whetstones
Industry
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
Medical Industry
-
-
Antiquity Uses
Monuments, Sculpture, Small Figurines
Artifacts
Other Uses
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
As a touchstone, Cemetery Markers, Creating Artwork
Types
Intermediate volcanic rock
Algoma-type , Lake Superior-type, Superior-type and Taconite
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
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
Olivine, Plagioclase, Pyroxene
Hematite, Magnetite, Quartz
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
Fe, Iron(III) Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Chemical Weathering, Mechanical Weathering
Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Coastal Erosion, Wind Erosion
Physical Properties
Hardness
3-45.5-6
1
7
👆🏻
Grain Size
Fine to Medium Grained
Large and Coarse Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Streak
Bluish Black
White
Porosity
Less Porous
Highly Porous
Luster
Grainy, Pearly and Vitreous
Earthy
Compressive Strength
200.00 N/mm2220.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
1.5
Specific Gravity
-99995.0-5.3
0
8.4
👆🏻
Transparency
Opaque
Translucent to Opaque
Density
-9999 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K3.20 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat 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
Ethiopia, Somalia, South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Iceland
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
Brazil
Bolivia, Brazil
Deposits in Oceania Continent
Australia
-
New South Wales, Queensland, South Australia, Western Australia