Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Origin
Hawaii Islands
Germany
Discoverer
Unknown
Van Tooren
Etymology
From Greek pikros bitter + -ite, 19th century
From Greek tephra, ashes from Indo-European base, to burn
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy, Rough
Aphanitic to Porphyritic
Color
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Vesicular
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
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.
Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Production of Lime, Soil Conditioner
Types
Oceanite
Not Available
Features
Host Rock for Lead
Host Rock for Lead
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
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.
Tephrite 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.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
CaO, Carbon Dioxide, 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
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Streak
White, Greenish White or Grey
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Cleavage
Imperfect
Crenulation and Pervasive
Specific Gravity
2.75-2.92
2.86
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Russia
Not Yet Found
Africa
South Africa
Namibia, Uganda
Europe
Iceland
Germany, Hungary, Italy, Portugal, Spain
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand, Western Australia
Picrite vs Tephrite 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 Tephrite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Picrite and Properties of Tephrite. Learn more about Picrite vs Tephrite in the next section. The interior uses of Picrite include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Tephrite include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Picrite and Tephrite, 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 Tephrite include Landscaping.
More about Picrite and Tephrite
Here you can know more about Picrite and Tephrite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Picrite and Tephrite consists of mineral content and compound content. The mineral content of Picrite includes Biotite, Olivine, Plagioclase, Pyrrhotite and mineral content of Tephrite includes Alkali feldspar, Nepheline, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Picrite vs Tephrite, the texture, color and appearance plays an important role in determining the type of rock. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas, Tephrite is available in black, brown, colourless, green, grey, white colors. Appearance of Picrite is Rough and Shiny and that of Tephrite is Vesicular. Properties of rock is another aspect for Picrite vs Tephrite. The hardness of Picrite is 6.8 and that of Tephrite is 6.5. The types of Picrite are Oceanite whereas types of Tephrite are Not Available. 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 Tephrite is bluish black. The specific heat capacity of Picrite is 0.88 kJ/Kg K and that of Tephrite is 0.92 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 Tephrite is heat resistant, impact resistant.