1 Definition
1.1 Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
1.2 History
1.2.1 Origin
Germany
Adak, Aleutian Islands
1.2.2 Discoverer
Van Tooren
Defant and Drummond
1.3 Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Adak, Aleutian Islands
1.4 Class
Igneous Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Aphanitic to Porphyritic
Porphyritic
2.2 Color
Black, Brown, Colourless, Green, Grey, White
Black, Brown, Light to Dark Grey
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, Flooring, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Office Buildings
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
Landscaping
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Sculpture
Monuments, Sculpture, Small Figurines
3.4 Other Uses
3.4.1 Commercial Uses
Production of Lime, Soil Conditioner
Commemorative Tablets, Pottery, Used in aquariums
4 Types
4.1 Types
Not Available
Not Available
4.2 Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Not Applicable
Data Not Available
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Data Not Available
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
5.2 Composition
5.2.1 Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Olivine, Plagioclase, Pyroxene
5.2.2 Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, MgO, Silicon Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Coastal Erosion, Sea Erosion, Water Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Medium to Fine Coarse Grained
Fine to Medium Grained
6.1.3 Fracture
6.1.4 Streak
Bluish Black
Bluish Black
6.1.5 Porosity
Very Less Porous
Less Porous
6.1.6 Luster
Subvitreous to Dull
Grainy, Pearly and Vitreous
6.1.7 Compressive Strength
6.1.8 Cleavage
Crenulation and Pervasive
Not Available
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
2.8-2.9 g/cm3Not Available
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
6.2.2 Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Not Yet Found
India, Russia
7.1.2 Africa
Namibia, Uganda
Ethiopia, Somalia, South Africa
7.1.3 Europe
Germany, Hungary, Italy, Portugal, Spain
Iceland
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
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, Western Australia
Not Yet Found