Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
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
Origin
Hawaii Islands
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
From Greek pikros bitter + -ite, 19th century
From Adak, Aleutian Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy, Rough
Porphyritic
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Rough and Shiny
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture
Monuments, Sculpture, Small Figurines
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Commemorative Tablets, Pottery, Used in aquariums
Types
Oceanite
Intermediate volcanic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Archaeological Significance
Formation
Picrite 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.
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.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Olivine, Plagioclase, Pyroxene
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Fine Grained
Fine to Medium Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
Bluish Black
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Grainy, Pearly and Vitreous
Specific Gravity
2.75-2.92
-9999
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
-9999 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
India, Russia
Africa
South Africa
Ethiopia, Somalia, South Africa
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Picrite vs Adakite 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. Picrite vs Adakite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Picrite and Properties of Adakite. Learn more about Picrite vs Adakite in the next section. The interior uses of Picrite include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens. Due to some exceptional properties of Picrite and Adakite, they have various applications in construction industry. The uses of Picrite in construction industry include As a sintering agent in steel industry to process iron ore, Cement manufacture, For road aggregate, Manufacture of magnesium and dolomite refractories, Roadstone, Used for flooring, stair treads, borders and window sills. and that of Adakite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Picrite and Adakite
Here you can know more about Picrite and Adakite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Picrite and Adakite consists of mineral content and compound content. The mineral content of Picrite includes Biotite, Olivine, Plagioclase, Pyrrhotite and mineral content of Adakite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Picrite vs Adakite, the texture, color and appearance plays an important role in determining the type of rock. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas, Adakite is available in black, brown, light to dark grey colors. Appearance of Picrite is Rough and Shiny and that of Adakite is Dull and Soft. Properties of rock is another aspect for Picrite vs Adakite. The hardness of Picrite is 6.8 and that of Adakite is 3-4. The types of Picrite are Oceanite whereas types of Adakite are Intermediate volcanic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Picrite is white, greenish white or grey while that of Adakite is bluish black. The specific heat capacity of Picrite is 0.88 kJ/Kg K and that of Adakite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Picrite is heat resistant whereas Adakite is heat resistant, pressure resistant, wear resistant.