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
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, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Black, Brown, 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
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
Greywacke
Igneous rock
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Host Rock for Lead
Archaeological Significance
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
-
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
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
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
-
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
Deposits in Western Continents
North America
Canada, USA
USA
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
New Zealand, Western Australia
Greywacke vs Tephrite 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. Greywacke vs Tephrite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Greywacke and Properties of Tephrite. Learn more about Greywacke vs Tephrite in the next section. The interior uses of Greywacke include Decorative aggregates, Floor tiles, Flooring, Homes and Interior decoration whereas the interior uses of Tephrite include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Greywacke and Tephrite, they have various applications in construction industry. The uses of Greywacke in construction industry include Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Raw material for the manufacture of mortar and that of Tephrite include Landscaping.
More about Greywacke and Tephrite
Here you can know more about Greywacke and Tephrite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Greywacke and Tephrite consists of mineral content and compound content. The mineral content of Greywacke includes Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz and mineral content of Tephrite includes Alkali feldspar, Nepheline, Plagioclase, Pyroxene. You can also check out the list of all Sedimentary Rocks. When we have to compare Greywacke vs Tephrite, the texture, color and appearance plays an important role in determining the type of rock. Greywacke is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors whereas, Tephrite is available in black, brown, green, grey, white colors. Appearance of Greywacke is Dull and that of Tephrite is Vesicular. Properties of rock is another aspect for Greywacke vs Tephrite. The hardness of Greywacke is 6-7 and that of Tephrite is 6.5. The types of Greywacke are Greywacke whereas types of Tephrite are Igneous rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Greywacke is white while that of Tephrite is bluish black. The specific heat capacity of Greywacke is 0.71 kJ/Kg K and that of Tephrite 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.Greywacke is heat resistant, impact resistant, pressure resistant whereas Tephrite is heat resistant, impact resistant.