Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
Unknown
Van Tooren
Etymology
From German Grauwacke, from grau grey + wacke
From Greek tephra, ashes from Indo-European base, to burn
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic
Aphanitic to Porphyritic
Color
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Vesicular
Interior Uses
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Sculpture
Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Production of Lime, Soil Conditioner
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Host Rock for Lead
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Formation
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
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.
Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
Not Applicable
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Angular and Fine
Medium to Fine Coarse Grained
Fracture
Conchoidal
Uneven
Streak
White
Bluish Black
Porosity
Highly Porous
Very Less Porous
Luster
Dull
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Perfect
Crenulation and Pervasive
Specific Gravity
2.2-2.8
2.86
Transparency
Opaque
Opaque
Density
2.6-2.61 g/cm3
2.8-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Not Yet Found
Africa
Namibia, Nigeria, South Africa
Namibia, Uganda
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Germany, Hungary, Italy, Portugal, Spain
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
New Zealand, Western Australia
All about Greywacke and Tephrite Properties
Know all about Greywacke and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Tephrite belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Tephrite is Aphanitic to Porphyritic. Greywacke appears Dull and Tephrite appears Vesicular. The luster of Greywacke is dull while that of Tephrite is subvitreous to dull. Greywacke and Tephrite are available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones and that of Tephrite are production of lime, soil conditioner.