1 Definition
1.1 Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From Greek tephra, ashes from Indo-European base, to burn
From the Middle High German verb gneist (to spark; so called because the rock glitters)
1.4 Class
Igneous Rocks
Metamorphic 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
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Aphanitic to Porphyritic
Banded, Foliated, Platy
2.2 Color
Black, Brown, Colourless, Green, Grey, White
Black, Brown, Pink, Red, 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, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
Landscaping
As Dimension Stone
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Sculpture
Artifacts
3.4 Other Uses
3.4.1 Commercial Uses
Production of Lime, Soil Conditioner
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
4 Types
4.1 Types
Not Available
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
4.2 Features
Host Rock for Lead
Generally rough to touch, Is one of the oldest rock
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Not Applicable
Konark Sun Temple in India, Washington Monument, US
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Not Applicable
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.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
5.2 Composition
5.2.1 Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
5.2.2 Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Impact Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Medium to Fine Coarse Grained
Medium to Coarse Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Very Less Porous
Very Less Porous
6.1.6 Luster
6.1.7 Compressive Strength
90.00 N/mm2125.00 N/mm2
0.15
450
6.1.8 Cleavage
Crenulation and Pervasive
Poor
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
Opaque
Translucent to Opaque
6.1.12 Density
2.8-2.9 g/cm32.6-2.9 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
6.2.2 Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Not Yet Found
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
7.1.2 Africa
Namibia, Uganda
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
7.1.3 Europe
Germany, Hungary, Italy, Portugal, Spain
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
7.1.4 Others
Not Yet Found
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
7.2.2 South America
Not Yet Found
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, Western Australia
New South Wales, New Zealand, Queensland, Victoria