Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
Origin
Germany
Pennines, England
Discoverer
Van Tooren
J.J. Ferber
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Grit + Stone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy
Color
Black, Brown, Green, Grey, White
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Layered and Foliated
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
Construction Aggregate, Roadstone
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Production of Lime, Soil Conditioner
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO), Tombstones
Types
Igneous rock
Sedimentary rock
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
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.
Gritstone is a type of sedimentary rock which was formed on the floors of wide river deltas where the grit deposits were laid down, with every tide or flood dumping another layer of sediment.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Calcite, Clay Minerals, Feldspar, Micas, Quartz
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
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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
Grain Size
Medium to Fine Coarse Grained
Coarse Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Cleavage
Crenulation and Pervasive
Perfect
Specific Gravity
2.86
2.250
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.2 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
-
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Namibia, Uganda
Namibia, Nigeria, South Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
Austria, Denmark, Germany, Great Britain, Netherlands, Poland, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, New Zealand, Western Australia
Tephrite vs Gritstone 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 Gritstone characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Tephrite and Properties of Gritstone. Learn more about Tephrite vs Gritstone in the next section. The interior uses of Tephrite include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Gritstone include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Tephrite and Gritstone, they have various applications in construction industry. The uses of Tephrite in construction industry include Landscaping and that of Gritstone include Construction aggregate, Roadstone.
More about Tephrite and Gritstone
Here you can know more about Tephrite and Gritstone. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Tephrite and Gritstone consists of mineral content and compound content. The mineral content of Tephrite includes Alkali feldspar, Nepheline, Plagioclase, Pyroxene and mineral content of Gritstone includes Calcite, Clay Minerals, Feldspar, Micas, Quartz. You can also check out the list of all Igneous Rocks. When we have to compare Tephrite vs Gritstone, 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, Gritstone is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. Appearance of Tephrite is Vesicular and that of Gritstone is Layered and Foliated. Properties of rock is another aspect for Tephrite vs Gritstone. The hardness of Tephrite is 6.5 and that of Gritstone is 6-7. The types of Tephrite are Igneous rock whereas types of Gritstone are Sedimentary rock. 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 Gritstone is white. The specific heat capacity of Tephrite is 0.92 kJ/Kg K and that of Gritstone 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 Gritstone is heat resistant, impact resistant, pressure resistant.