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
  
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
  
History
  
  
Origin
Adak, Aleutian Islands
  
Brazil
  
Discoverer
Defant and Drummond
  
Unknown
  
Etymology
From Adak, Aleutian Islands
  
from French néphéline, from Greek nephelē
  
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
  
Fine Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Aphanitic
  
Color
Black, Brown, Light to Dark Grey
  
Black, Brown, Colourless, Green, Grey, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull and Soft
  
Skeletal
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
  
Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
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
  
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
  
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
  
Types
Not Available
  
Peralkaline Nephelinite
  
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
  
Host Rock for Lead
  
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.
  
Nephelinite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Clinopyroxene, Nepheline, Plagioclase
  
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
  
Ca, CaO, Carbon, Cl, MgO
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Contact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
  
Chemical Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
3-4
  
6.5
  
Grain Size
Fine to Medium Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Flat
  
Streak
Bluish Black
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Grainy, Pearly and Vitreous
  
Vitreous to Metallic
  
Compressive Strength
Not Available
  
35.00 N/mm
2
  
29
Cleavage
Not Available
  
Imperfect
  
Toughness
Not Available
  
2.7
  
Specific Gravity
Not Available
  
2.4-2.9
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.5-3 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.88 kJ/Kg K
  
13
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Japan
  
Africa
Ethiopia, Somalia, South Africa
  
Rwanda, Tanzania
  
Europe
Iceland
  
Not Yet Found
  
Others
Not Yet Found
  
Hawaii Islands
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Colombia
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
Not Yet Found
  
Adakite vs Nephelinite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Adakite vs Nephelinite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Adakite and Properties of Nephelinite. Learn more about Adakite vs Nephelinite in the next section. The interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens whereas the interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Adakite and Nephelinite, they have various applications in construction industry. The uses of Adakite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Nephelinite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate.
More about Adakite and Nephelinite
Here you can know more about Adakite and Nephelinite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Adakite and Nephelinite consists of mineral content and compound content. The mineral content of Adakite includes Olivine, Plagioclase, Pyroxene and mineral content of Nephelinite includes Clinopyroxene, Nepheline, Plagioclase. You can also check out the list of all Igneous Rocks. When we have to compare Adakite vs Nephelinite, the texture, color and appearance plays an important role in determining the type of rock. Adakite is available in black, brown, light to dark grey colors whereas, Nephelinite is available in black, brown, colourless, green, grey, white colors. Appearance of Adakite is Dull and Soft and that of Nephelinite is Skeletal. Properties of rock is another aspect for Adakite vs Nephelinite. The hardness of Adakite is 3-4 and that of Nephelinite is 6.5. The types of Adakite are Not Available whereas types of Nephelinite are Peralkaline Nephelinite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Adakite is bluish black while that of Nephelinite is white. The specific heat capacity of Adakite is Not Available and that of Nephelinite is 0.88 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Adakite is heat resistant, pressure resistant, wear resistant whereas Nephelinite is heat resistant.