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
Discoverer
Van Tooren
Obsius
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Opaque Rock
Texture
Aphanitic to Porphyritic
Glassy
Color
Black, Brown, Green, Grey, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Shiny
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Garden Decoration
Other Architectural Uses
Curbing
-
Construction Industry
Landscaping
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery
Commercial Uses
Production of Lime, Soil Conditioner
Creating Artwork, Mirror, Used in aquariums
Types
Igneous rock
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Host Rock for Lead
Blocks negativity, Helps to protect against depression
Archaeological Significance
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.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
-
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
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium to Fine Coarse Grained
-
Fracture
Uneven
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Vitreous
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.86
2.6-2.7
Transparency
Opaque
Translucent
Density
2.8-2.9 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
-
Afghanistan, Indonesia, Japan, Russia
Africa
Namibia, Uganda
Kenya
Europe
Germany, Hungary, Italy, Portugal, Spain
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
-
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand
Tephrite vs Obsidian Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Tephrite vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Tephrite and Properties of Obsidian. Learn more about Tephrite vs Obsidian in the next section. The interior uses of Tephrite include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Tephrite and Obsidian, they have various applications in construction industry. The uses of Tephrite in construction industry include Landscaping and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Tephrite and Obsidian
Here you can know more about Tephrite and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Tephrite and Obsidian consists of mineral content and compound content. The mineral content of Tephrite includes Alkali feldspar, Nepheline, Plagioclase, Pyroxene and mineral content of Obsidian includes . You can also check out the list of all Igneous Rocks. When we have to compare Tephrite vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Tephrite is available in black, brown, green, grey, white colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Tephrite is Vesicular and that of Obsidian is Shiny. Properties of rock is another aspect for Tephrite vs Obsidian. The hardness of Tephrite is 6.5 and that of Obsidian is 5-5.5. The types of Tephrite are Igneous rock whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Tephrite is bluish black while that of Obsidian is white. The specific heat capacity of Tephrite is 0.92 kJ/Kg K and that of Obsidian is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Tephrite is heat resistant, impact resistant whereas Obsidian is heat resistant, impact resistant.