Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
A water-soluble mineral sediment resulting from concentration and crystallization by evaporation from an aqueous solution
History
Origin
Germany
USA
Discoverer
Van Tooren
Usiglio
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From a sediment left after the evaporation
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Family
Group
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
Earthy
Color
Black, Brown, Green, Grey, White
Green, Grey, Silver, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Glassy, Vesicular and Foilated
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, 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
Industry
Construction Industry
Landscaping
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Sculpture
Artifacts
Other Uses
Commercial Uses
Production of Lime, Soil Conditioner
Used in the manufacture of Ceramic Powder, Used in the preparation of Sulfuric Acid and Silicon Diborite
Types
Igneous rock
Sedimentary rock
Features
Host Rock for Lead
Generally rough to touch, Splintery, Veined
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
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.
Evaporite is water-soluble mineral sediment which forms from concentration and crystallization by evaporation from an aqueous solution.
Composition
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Calcite, Cancrinite, Gypsum, Kyanite, Magnetite
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
CaMg(CO3)2, CaO, Calcium Sulfate, KCl, MgO, NaCl
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
-
Physical Properties
Hardness
6.52-3
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Compressive Strength
90.00 N/mm2225.00 N/mm2
0.15
450
👆🏻
Cleavage
Crenulation and Pervasive
Perfect
Toughness
2.4
-
Specific Gravity
2.862.86-2.99
0
8.4
👆🏻
Transparency
Opaque
Translucent
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, Pressure Resistant
Deposits in Eastern Continents
Asia
-
-
Africa
Namibia, Uganda
-
Europe
Germany, Hungary, Italy, Portugal, Spain
United Kingdom
Others
-
-
Deposits in Western Continents
North America
USA
USA
South America
-
Colombia, Paraguay
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Central Australia, Western Australia