Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
History
Origin
Germany
Germany
Discoverer
Van Tooren
Van Tooren
Etymology
From Greek tephra, ashes from Indo-European base, to burn
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
Family
Group
Volcanic
Volcanic
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
Aphanitic to Porphyritic
Color
Black, Brown, Green, Grey, White
Black, Brown, Green, Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Vesicular
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Landscaping
Landscaping
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture
Artifacts, Sculpture
Other Uses
Commercial Uses
Production of Lime, Soil Conditioner
Production of Lime, Soil Conditioner
Types
Igneous rock
Igneous rock
Features
Host Rock for Lead
Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
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.
Composition
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Physical Properties
Hardness
6.56.5
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Uneven
Streak
Bluish Black
Bluish Black
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Compressive Strength
90.00 N/mm290.00 N/mm2
0.15
450
👆🏻
Cleavage
Crenulation and Pervasive
Crenulation and Pervasive
Toughness
2.4
2.4
Specific Gravity
2.862.86
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
-
-
Africa
Namibia, Uganda
Namibia, Uganda
Europe
Germany, Hungary, Italy, Portugal, Spain
Germany, Hungary, Italy, Portugal, Spain
Others
-
-
Deposits in Western Continents
North America
USA
USA
South America
-
-
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand, Western Australia