Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Sandstone is defined as a rock which is composed of sand-sized grains of various minerals mostly of uniform size and often are smooth and rounded
History
Origin
Germany
-
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From its composition, sand and stone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Clastic, Granular, Rough
Color
Black, Brown, Green, Grey, White
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Rough
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Landscaping
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Production of Lime, Soil Conditioner
An Oil and Gas Reservoir, In aquifers, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones, Used in aquariums
Types
Igneous rock
Grey Sandstones, Crystallized Sandstones, Hard Sandstones , Carbonate Cemented Sandstones and Ganister
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Abu Simbel in Egypt, Agia Sophia in Istanbul, Turkey, Angkor Wat in Cambodia, Buland Darwaza in Agra, India, Chhatrapati Shivaji Terminus in Maharashtra, India, Dom in Berlin, Great Sphinx at Giza, Egypt, Hawa Mahal in Jaipur, India, Humayun's Tomb in Delhi, India, India Gate in Delhi, India, Jama Masjid in Delhi, India, Khajuraho Temples, India, Leh Palace in Leh, India, Lotus Temple in New Delhi, India, Luxor Temple in Egypt, Machu Picchu in Peru, Neuschwanstein in Bavaria, Petra in Jordan, Qutb Minar in India, Red Fort in Delhi, India, Sanchi Stupa in India
Sculpture
-
-
Famous Sculptures
-
Ajanta Caves in Maharashtra, India, Elephanta Caves in Maharashtra, India, Mount Rushmore National Memorial in South Dakota, US
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.
Sandstone is a sedimentary rock which forms from cemented sand-sized clasts. It forms when sand layers are buried under sediments of sand.
Composition
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Calcite, Clay, 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
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
6.56-7
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Coarse or Fine
Fracture
Uneven
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Compressive Strength
90.00 N/mm295.00 N/mm2
0.15
450
👆🏻
Cleavage
Crenulation and Pervasive
Perfect
Toughness
2.4
2.6
Specific Gravity
2.862.2-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm32.2-2.8 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, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
-
China, India, Kazakhstan, Mongolia, Russia, Thailand, Uzbekistan
Africa
Namibia, Uganda
Namibia, Nigeria, South Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
-
Greenland
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Brazil
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, New Zealand