1 Definition
1.1 Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From German Grauwacke, from grau grey + wacke
From the Middle High German verb gneist (to spark; so called because the rock glitters)
1.4 Class
Sedimentary Rocks
Metamorphic Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
1.5 Family
1.5.1 Group
Not Applicable
Not Applicable
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Clastic
Banded, Foliated, Platy
2.2 Color
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Black, Brown, Pink, Red, White
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
3.1.3 Other Architectural Uses
Curbing, Whetstones
Curbing
3.2 Industry
3.2.1 Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
As Dimension Stone
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts
3.4 Other Uses
3.4.1 Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
4 Types
4.1 Types
Not Available
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
4.2 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
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Not Applicable
Konark Sun Temple in India, Washington Monument, US
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Not Applicable
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
5.2 Composition
5.2.1 Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
5.2.2 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, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Not Applicable
Impact Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Angular and Fine
Medium to Coarse Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Highly Porous
Very Less Porous
6.1.6 Luster
6.1.7 Compressive Strength
6.1.8 Cleavage
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
Opaque
Translucent to Opaque
6.1.12 Density
2.6-2.61 g/cm32.6-2.9 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
6.2.2 Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
7.1.2 Africa
Namibia, Nigeria, South Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
7.1.3 Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
7.1.4 Others
7.2 Deposits in Western Continents
7.2.1 North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
7.2.2 South America
Brazil
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
7.3 Deposits in Oceania Continent
7.3.1 Australia
New South Wales, New Zealand
New South Wales, New Zealand, Queensland, Victoria