Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
  
Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts
  
History
  
  
Discoverer
Unknown
  
Unknown
  
Etymology
From German Grauwacke, from grau grey + wacke
  
From Latin term that means purple
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine 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, Pink, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Dull
  
Rough
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
  
Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing, Whetstones
  
Curbing
  
Industry
  
  
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
  
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
  
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)
  
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
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Absent
  
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.
  
Rhomb-porphyry 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.
  
Composition
  
  
Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
  
Alkali feldspar, Biotite, 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, Cl, MgO
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6-7
  
5-5.5
  
Grain Size
Angular and Fine
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Very Less Porous
  
Luster
Dull
  
Subvitreous to Dull
  
Compressive Strength
Not Available
  
310.00 N/mm
2
  
2
Cleavage
Perfect
  
Perfect
  
Toughness
2.6
  
2.7
  
Specific Gravity
2.2-2.8
  
2.86
  
Transparency
Opaque
  
Translucent
  
Density
2.6-2.61 g/cm3
  
2.8-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
Not Yet Found
  
Africa
Namibia, Nigeria, South Africa
  
Not Yet Found
  
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
Bulgaria
  
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
  
Not Yet Found
  
All about Greywacke and Rhomb Porphyry Properties
Know all about Greywacke and Rhomb Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Rhomb Porphyry belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Rhomb Porphyry is Aphanitic to Porphyritic. Greywacke appears Dull and Rhomb Porphyry appears Rough. The luster of Greywacke is dull while that of Rhomb Porphyry is subvitreous to dull. Greywacke and Rhomb Porphyry 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 Rhomb Porphyry are an oil and gas reservoir, as a feed additive for livestock, metallurgical flux, soil conditioner, source of magnesia (mgo).