Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From German Grauwacke, from grau grey + wacke
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Types
Not Available
Not Available
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Used
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
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.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Not Applicable
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering
Types of Erosion
Not Applicable
Coastal Erosion, Sea Erosion, Wind Erosion
Grain Size
Very fine-grained
Angular and Fine
Fracture
Uneven
Conchoidal
Streak
Light to dark brown
White
Porosity
Less Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Irregular
Perfect
Toughness
Not Available
2.6
Specific Gravity
2.46-2.86
2.2-2.8
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
2.6-2.61 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
South Korea
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Western Africa
Namibia, Nigeria, South Africa
Europe
Great Britain, Switzerland
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Not Yet Found
Canada, USA
South America
Not Yet Found
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand
All about Pseudotachylite and Greywacke Properties
Know all about Pseudotachylite and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite belongs to Metamorphic Rocks while Greywacke belongs to Sedimentary Rocks.Texture of Pseudotachylite is Quench whereas that of Greywacke is Clastic. Pseudotachylite appears Dull and Soft and Greywacke appears Dull. The luster of Pseudotachylite is vitreous while that of Greywacke is dull. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas Greywacke is 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 Pseudotachylite are creating artwork, gemstone and that of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.