1 Definition
1.1 Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From Greek tephra, ashes from Indo-European base, to burn
1.4 Class
Metamorphic Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Quench
Aphanitic to Porphyritic
2.2 Color
Black, Brown, Colourless, Green, Grey, Pink, White
Black, Brown, Colourless, Green, Grey, White
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Landscaping
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture
3.4 Other Uses
3.4.1 Commercial Uses
Creating Artwork, Gemstone
Production of Lime, Soil Conditioner
4 Types
4.1 Types
Not Available
Not Available
4.2 Features
Host Rock for Lead
Host Rock for Lead
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Data Not Available
Not Applicable
4.3.3 Sculpture
4.3.4 Famous Sculptures
Not Applicable
Data Not Available
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
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.
5.2 Composition
5.2.1 Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
5.2.2 Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
CaO, Carbon Dioxide, MgO, Silicon Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Not Applicable
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Very fine-grained
Medium to Fine Coarse Grained
6.1.3 Fracture
6.1.4 Streak
Light to dark brown
Bluish Black
6.1.5 Porosity
Less Porous
Very Less Porous
6.1.6 Luster
Vitreous
Subvitreous to Dull
6.1.7 Compressive Strength
60.00 N/mm290.00 N/mm2
0.15
450
6.1.8 Cleavage
Irregular
Crenulation and Pervasive
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
Transparent to Translucent
Opaque
6.1.12 Density
2.7-2.9 g/cm32.8-2.9 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
6.2.2 Resistance
Heat Resistant
Heat Resistant, Impact Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
South Korea
Not Yet Found
7.1.2 Africa
Western Africa
Namibia, Uganda
7.1.3 Europe
Great Britain, Switzerland
Germany, Hungary, Italy, Portugal, Spain
7.1.4 Others
Not Yet Found
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
7.2.2 South America
Not Yet Found
Not Yet Found
7.3 Deposits in Oceania Continent
7.3.1 Australia
Central Australia, Western Australia
New Zealand, Western Australia