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Tephrite
Tephrite

Obsidian
Obsidian



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Tephrite
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Obsidian

Tephrite and Obsidian

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1 Definition
1.1 Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
1.2 History
1.2.1 Origin
Germany
Ethiopia
1.2.2 Discoverer
Van Tooren
Obsius
1.3 Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
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
Volcanic
Volcanic
1.6 Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Opaque Rock
2 Texture
2.1 Texture
Aphanitic to Porphyritic
Glassy
2.2 Color
Black, Brown, Colourless, Green, Grey, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
2.3 Maintenance
Less
Less
2.4 Durability
Durable
Durable
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
Vesicular
Shiny
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Garden Decoration
3.1.3 Other Architectural Uses
Curbing
Not Yet Used
3.2 Industry
3.2.1 Construction Industry
Landscaping
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
3.2.2 Medical Industry
Not Yet Used
Surgery
3.3 Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery
3.4 Other Uses
3.4.1 Commercial Uses
Production of Lime, Soil Conditioner
Creating Artwork, Mirror, Used in aquariums
4 Types
4.1 Types
Not Available
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
4.2 Features
Host Rock for Lead
Blocks negativity, Helps to protect against depression
4.3 Archaeological Significance
4.3.1 Monuments
Not Yet Used
Not Yet Used
4.3.2 Famous Monuments
Not Applicable
Not Applicable
4.3.3 Sculpture
Used
Not Yet Used
4.3.4 Famous Sculptures
Data Not Available
Not Applicable
4.3.5 Pictographs
Not Used
Used
4.3.6 Petroglyphs
Not Used
Used
4.3.7 Figurines
Used
Not Yet Used
4.4 Fossils
Absent
Absent
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.
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
5.2 Composition
5.2.1 Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Not Available
5.2.2 Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, 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
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological 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
Chemical Erosion, Coastal Erosion, Glacier Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.55-5.5
Coal
1 7
6.1.2 Grain Size
Medium to Fine Coarse Grained
Not Applicable
6.1.3 Fracture
Uneven
Conchoidal
6.1.4 Streak
Bluish Black
White
6.1.5 Porosity
Very Less Porous
Very Less Porous
6.1.6 Luster
Subvitreous to Dull
Vitreous
6.1.7 Compressive Strength
90.00 N/mm20.15 N/mm2
Slate
0.15 450
6.1.8 Cleavage
Crenulation and Pervasive
Non-Existent
6.1.9 Toughness
2.4
Not Available
6.1.10 Specific Gravity
2.862.6-2.7
Granite
0 8.4
6.1.11 Transparency
Opaque
Translucent
6.1.12 Density
2.8-2.9 g/cm32.6 g/cm3
Granite
0 1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K0.92 kJ/Kg K
What Is Granulite
0.14 3.2
6.2.2 Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Not Yet Found
Afghanistan, Indonesia, Japan, Russia
7.1.2 Africa
Namibia, Uganda
Kenya
7.1.3 Europe
Germany, Hungary, Italy, Portugal, Spain
Greece, Hungary, Iceland, Italy, Turkey
7.1.4 Others
Not Yet Found
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
USA
Canada, Mexico, USA
7.2.2 South America
Not Yet Found
Argentina, Chile, Ecuador, Peru
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, Western Australia
New Zealand

All about Tephrite and Obsidian Properties

Know all about Tephrite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite and Obsidian belong to Igneous Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Obsidian is Glassy. Tephrite appears Vesicular and Obsidian appears Shiny. The luster of Tephrite is subvitreous to dull while that of Obsidian is vitreous. Tephrite is available in black, brown, colourless, green, grey, white colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Obsidian are creating artwork, mirror, used in aquariums.