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
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Origin
Adak, Aleutian Islands
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Discoverer
Defant and Drummond
R. J. Hauy
Etymology
From Adak, Aleutian Islands
From Greek pegma, pegmat which means- thing joined together + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Porphyritic
Pegmatitic
Color
Black, Brown, Light to Dark Grey
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Durability
Durable
Durable
Appearance
Dull and Soft
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
As Building Stone, As Facing Stone, Paving Stone
Other Architectural Uses
Whetstones
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
Antiquity Uses
Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
Types
Intermediate volcanic rock
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Archaeological Significance
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.
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Mineral Content
Olivine, Plagioclase, Pyroxene
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine to Medium Grained
Medium to Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
Bluish Black
White
Porosity
Less Porous
Less Porous
Luster
Grainy, Pearly and Vitreous
Grainy, Pearly and Vitreous
Specific Gravity
-9999
2.6-2.63
Transparency
Opaque
Translucent to Opaque
Density
-9999 g/cm3
2.6-2.65 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Africa
Ethiopia, Somalia, South Africa
South Africa
Europe
Iceland
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
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New South Wales, Queensland, South Australia, Western Australia
Adakite vs Pegmatite 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 Pegmatite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Adakite and Properties of Pegmatite. Learn more about Adakite vs Pegmatite in the next section. The interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens whereas the interior uses of Pegmatite include Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Adakite and Pegmatite, 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 Pegmatite include As dimension stone, Building houses or walls, Construction aggregate, For road aggregate, Landscaping.
More about Adakite and Pegmatite
Here you can know more about Adakite and Pegmatite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Adakite and Pegmatite consists of mineral content and compound content. The mineral content of Adakite includes Olivine, Plagioclase, Pyroxene and mineral content of Pegmatite includes Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz. You can also check out the list of all Igneous Rocks. When we have to compare Adakite vs Pegmatite, 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, Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. Appearance of Adakite is Dull and Soft and that of Pegmatite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Adakite vs Pegmatite. The hardness of Adakite is 3-4 and that of Pegmatite is 7. The types of Adakite are Intermediate volcanic rock whereas types of Pegmatite are Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite. 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 Pegmatite is white. The specific heat capacity of Adakite is 0.84 kJ/Kg K and that of Pegmatite is 0.79 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 Pegmatite is heat resistant, impact resistant, pressure resistant.