Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Metapelite is an old and currently not widely used field geological term for a clay rich fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Pelos or clay in Greek
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Volcanic
Not Applicable
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Foliated
Color
Black, Brown, Colourless, Green, Grey, White
Dark Greenish - Grey, Green, Light Green, Light Greenish Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Banded
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture
Artifacts
Commercial Uses
Production of Lime, Soil Conditioner
Commemorative Tablets, Creating Artwork
Types
Not Available
Not Available
Features
Host Rock for Lead
Easily splits into thin plates, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Used
Not Yet 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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Metapelite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Albite, Chlorite, Quartz
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, MgO
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Streak
Bluish Black
Unknown
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Earthy
Compressive Strength
Not Available
Cleavage
Crenulation and Pervasive
Not Available
Toughness
2.4
Not Available
Specific Gravity
2.86
3.4-3.7
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
0-300 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
Not Yet Found
Africa
Namibia, Uganda
Western Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Not Available
South America
Not Yet Found
Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Central Australia, Western Australia
All about Tephrite and Metapelite Properties
Know all about Tephrite and Metapelite properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite belongs to Igneous Rocks while Metapelite belongs to Metamorphic Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Metapelite is Foliated. Tephrite appears Vesicular and Metapelite appears Banded. The luster of Tephrite is subvitreous to dull while that of Metapelite is earthy. Tephrite is available in black, brown, colourless, green, grey, white colors whereas Metapelite is available in dark greenish - grey, green, light green, light greenish grey colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Metapelite are commemorative tablets, creating artwork.