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
  
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
  
History
  
  
Origin
Adak, Aleutian Islands
  
USA
  
Discoverer
Defant and Drummond
  
John Peter Salley
  
Etymology
From Adak, Aleutian Islands
  
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
  
Class
Igneous Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Amorphous, Glassy
  
Color
Black, Brown, Light to Dark Grey
  
Black, Brown, Dark Brown, Grey, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
No
  
Scratch Resistant
No
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Dull and Soft
  
Veined or Pebbled
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
  
Not Yet Used
  
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
  
Not Yet Used
  
Other Architectural Uses
Whetstones
  
Not Yet Used
  
Industry
  
  
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Monuments, Sculpture, Small Figurines
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
  
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
  
Types
Not Available
  
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
  
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
  
Helps in production of Heat and Electricity, Used as fossil fuel
  
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
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Used
  
Not Yet Used
  
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.
  
Coal forms from the accumulation of plant debris in a swamp environment which is buried by sediments such as mud or sand and then compacted to form coal.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Analcime, Apatite, Barite, Calcite, Chalcopyrite, Chlorite, Chromite, Clausthalite, Clay Minerals, Crandallite Group, Dolomite, Feldspar, Galena, Gypsum, Marcasite, Muscovite or Illite, Pyrite, Quartz, Siderite, Sphalerite, Zircon
  
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
  
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
No
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Not Applicable
  
Erosion
Yes
  
No
  
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
  
Not Applicable
  
Physical Properties
  
  
Hardness
3-4
  
1-1.5
  
Grain Size
Fine to Medium Grained
  
Medium to Fine Coarse Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Bluish Black
  
Black
  
Porosity
Less Porous
  
Less Porous
  
Luster
Grainy, Pearly and Vitreous
  
Dull to Vitreous to Submetallic
  
Cleavage
Not Available
  
Non-Existent
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
Not Available
  
1.1-1.4
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
1100-1400 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
1.32 kJ/Kg K
  
4
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
  
Africa
Ethiopia, Somalia, South Africa
  
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
  
Europe
Iceland
  
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, Mexico, USA
  
South America
Brazil
  
Brazil, Chile, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New South Wales, Queensland, Victoria