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