Definition
A yellow sandstone which is flexible when cut into thin strips
  
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
  
History
  
  
Discoverer
Unknown
  
Unknown
  
Etymology
From the name of a mountain range where it was found; Itacolumi mountain in Brazil
  
From the Middle High German verb gneist (to spark; so called because the rock glitters)
  
Class
Sedimentary Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Clastic, Granular, Rough
  
Banded, Foliated, Platy
  
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
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Rough
  
Foliated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
  
Countertops, Decorative Aggregates, Flooring, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
  
As Dimension Stone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts
  
Other Uses
  
  
Commercial Uses
An Oil and Gas Reservoir, In aquifers, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones
  
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
  
Types
Not Available
  
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
  
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
  
Generally rough to touch, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Konark Sun Temple in India, Washington Monument, US
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Present
  
Absent
  
Formation
Itacolumite is a sedimentary rock which forms from cemented sand-sized clasts and is a type of sandstone.
  
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.
  
Composition
  
  
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
  
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
  
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Sea Erosion
  
Physical Properties
  
  
Hardness
6-7
  
7
  
Grain Size
Coarse or Fine
  
Medium to Coarse Grained
  
Fracture
Conchoidal
  
Irregular
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Very Less Porous
  
Luster
Dull
  
Dull
  
Compressive Strength
95.00 N/mm2
  
20
125.00 N/mm2
  
17
Cleavage
Perfect
  
Poor
  
Toughness
2.6
  
1.2
  
Specific Gravity
2.2-2.8
  
2.5-2.7
  
Transparency
Opaque
  
Translucent to Opaque
  
Density
2.2-2.8 g/cm3
  
2.6-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
  
Africa
Namibia, Nigeria, South Africa
  
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
  
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
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, Costa Rica, Cuba, Mexico, Panama, USA
  
South America
Brazil
  
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand
  
New South Wales, New Zealand, Queensland, Victoria