1 Definition
1.1 Definition
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
Unknown
1.2.2 Discoverer
Unknown
1.3 Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
1.4 Class
Metamorphic Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
1.5 Family
1.5.1 Group
Not Applicable
1.6 Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Banded, Foliated, Platy
2.2 Color
Black, Brown, Pink, Red, White
2.3 Maintenance
More
2.4 Durability
Durable
2.4.1 Water Resistant
✔
✘
81% - Metamorphic Rocks Rocks have it !
▶
2.4.2 Scratch Resistant
✔
✘
65% - Metamorphic Rocks Rocks have it !
▶
2.4.3 Stain Resistant
✔
✘
42% - Metamorphic Rocks Rocks have it !
▶
2.4.4 Wind Resistant
✔
✘
19% - Metamorphic Rocks Rocks have it !
▶
2.4.5 Acid Resistant
✔
✘
15% - Metamorphic Rocks Rocks have it !
▶
2.5 Appearance
Foliated
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
3.1.3 Other Architectural Uses
Curbing
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone
3.2.2 Medical Industry
Not Yet Used
3.3 Antiquity Uses
Artifacts
3.4 Other Uses
3.4.1 Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
4 Types
4.1 Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
4.2 Features
Generally rough to touch, Is one of the oldest rock
4.3 Archaeological Significance
4.3.1 Monuments
Used
4.3.2 Famous Monuments
Konark Sun Temple in India, Washington Monument, US
4.3.3 Sculpture
Not Yet Used
4.3.4 Famous Sculptures
Not Applicable
4.3.5 Pictographs
Not Used
4.3.6 Petroglyphs
Not Used
4.3.7 Figurines
Not Yet Used
4.4 Fossils
Absent
5 Formation
5.1 Formation
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
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
5.2.2 Compound Content
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
✔
✘
50% - Metamorphic Rocks Rocks have it !
▶
5.3.2 Types of Metamorphism
Impact Metamorphism
5.3.3 Weathering
✔
✘
65% - Metamorphic Rocks Rocks have it !
▶
5.3.4 Types of Weathering
Biological Weathering, Mechanical Weathering
5.3.5 Erosion
✔
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77% - Metamorphic Rocks Rocks have it !
▶
5.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Medium to Coarse Grained
6.1.3 Fracture
Irregular
6.1.4 Streak
White
6.1.5 Porosity
Very Less Porous
6.1.6 Luster
Dull
6.1.7 Compressive Strength
6.1.8 Cleavage
Poor
6.1.9 Toughness
1.2
6.1.10 Specific Gravity
6.1.11 Transparency
Translucent to Opaque
6.1.12 Density
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
6.2.2 Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
7.1.2 Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
7.1.3 Europe
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
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
7.2.2 South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
7.3 Deposits in Oceania Continent
7.3.1 Australia
New South Wales, New Zealand, Queensland, Victoria