Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
Origin
-
Webster, North Carolina
Discoverer
Unknown
Unknown
Etymology
From German Grauwacke, from grau grey + wacke
From the town of Webster located in North Carolina
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, Opaque Rock
Texture
Clastic
Clastic, Granular, Phaneritic, Porphyritic
Color
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
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
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts
Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Greywacke
Ultramafic rock
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Generally rough to touch, Is one of the oldest rock
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.
Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.
Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, 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
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
-
Burial Metamorphism, Impact 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, Water Erosion, Wind Erosion
Grain Size
Angular and Fine
Coarse Grained
Fracture
Conchoidal
Uneven
Streak
White
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Dull
Dull to Vitreous to Submetallic
Specific Gravity
2.2-2.8
3.2-3.5
Transparency
Opaque
Opaque
Density
2.6-2.61 g/cm3
3.1-3.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
India, Russia
Africa
Namibia, Nigeria, South Africa
South Africa
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
New Zealand, Queensland
All about Greywacke and Websterite Properties
Know all about Greywacke and Websterite properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Websterite belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Websterite is Clastic, Granular, Phaneritic, Porphyritic. Greywacke appears Dull and Websterite appears Layered, Banded, Veined and Shiny. The luster of Greywacke is dull while that of Websterite is dull to vitreous to submetallic. Greywacke is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors whereas Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. The commercial uses of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones and that of Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.