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
  
Borolanite is a variety of Nepheline Syenite and belongs to igneous rocks and contains nepheline-alkali feldspar pseudomorphs which occur as conspicuous white spots in the dark rock matrix
  
History
  
  
Origin
Adak, Aleutian Islands
  
Scotland
  
Discoverer
Defant and Drummond
  
Unknown
  
Etymology
From Adak, Aleutian Islands
  
From Alkalic Igneous complex near Loch Borralan in northwest Scotland
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Volcanic
  
Plutonic
  
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Granular
  
Color
Black, Brown, Light to Dark Grey
  
Brown, Buff, Cream, Green, Grey, Pink, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
No
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull and Soft
  
Banded and Foilated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
  
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Whetstones
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
  
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
  
Cemetery Markers
  
Types
Not Available
  
Not Available
  
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
  
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest 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
  
Used
  
Petroglyphs
Used
  
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.
  
Borolanites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
  
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
  
Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
  
Wind Erosion
  
Physical Properties
  
  
Hardness
3-4
  
5.5-6
  
Grain Size
Fine to Medium Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal to Uneven
  
Streak
Bluish Black
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Grainy, Pearly and Vitreous
  
Greasy to Dull
  
Compressive Strength
Not Available
  
150.00 N/mm
2
  
14
Cleavage
Not Available
  
Poor
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
Not Available
  
2.6
  
Transparency
Opaque
  
Translucent to Opaque
  
Density
Not Available
  
2.6 g/cm3
  
Thermal Properties
  
  
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
  
Africa
Ethiopia, Somalia, South Africa
  
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
  
Europe
Iceland
  
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Brazil, Chile, Colombia, Uruguay, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New Zealand, Queensland, South Australia, Tasmania, Western Australia