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
  
Alkali feldspar granite, also known as red granite, is a felsic igneous rock and a type of granite rich in the mineral potassium feldspar
  
History
  
  
Origin
Adak, Aleutian Islands
  
Unknown
  
Discoverer
Defant and Drummond
  
Unknown
  
Etymology
From Adak, Aleutian Islands
  
From mineral fledspar which is present in large quantities in this rock
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Volcanic
  
Plutonic
  
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Coarse Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Phaneritic
  
Color
Black, Brown, Light to Dark Grey
  
Black, Grey, Orange, Pink, White
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull and Soft
  
Veined or Pebbled
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
  
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Homes, Hotels, Kitchens, Stair Treads
  
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
  
As Building Stone, As Facing Stone, Bridges, Paving Stone, Near Swimming Pools, Office Buildings, Resorts
  
Other Architectural Uses
Whetstones
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
As Dimension Stone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
  
Curling, Gemstone, Laboratory bench tops, Tombstones
  
Types
Not Available
  
Not Available
  
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
  
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
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.
  
Alkali fledspar granite is an intrusive igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
  
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Contact Metamorphism, Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
  
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
3-4
  
6-7
  
Grain Size
Fine to Medium Grained
  
Large and Coarse Grained
  
Fracture
Conchoidal
  
Not Available
  
Streak
Bluish Black
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Grainy, Pearly and Vitreous
  
Dull to Grainy with Sporadic parts Pearly and Vitreous
  
Compressive Strength
Not Available
  
175.00 N/mm
2
  
13
Cleavage
Not Available
  
Not Available
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
Not Available
  
2.6-2.7
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.6-2.8 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.79 kJ/Kg K
  
16
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
  
Africa
Ethiopia, Somalia, South Africa
  
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
  
Europe
Iceland
  
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic, Venezuela
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
Not Yet Found