Definition
A water-soluble mineral sediment resulting from concentration and crystallization by evaporation from an aqueous solution
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
Origin
USA
-
Discoverer
Usiglio
Unknown
Etymology
From a sediment left after the evaporation
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy
Banded, Foliated, Platy
Color
Green, Grey, Silver, White
Black, Brown, Pink, Red, White
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Glassy, Vesicular and Foilated
Foliated
Architecture
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
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
As Dimension Stone
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts
Artifacts
Other Uses
Commercial Uses
Used in the manufacture of Ceramic Powder, Used in the preparation of Sulfuric Acid and Silicon Diborite
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Sedimentary rock
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Generally rough to touch, Splintery, Veined
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Konark Sun Temple in India, Washington Monument, US
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
Evaporite is water-soluble mineral sediment which forms from concentration and crystallization by evaporation from an aqueous solution.
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, Cancrinite, Gypsum, Kyanite, Magnetite
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
CaMg(CO3)2, CaO, Calcium Sulfate, KCl, MgO, NaCl
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
-
Biological Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Sea Erosion
Physical Properties
Hardness
2-37
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Medium to Coarse Grained
Fracture
Conchoidal
Irregular
Streak
White
White
Porosity
Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Dull
Compressive Strength
225.00 N/mm2125.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
-
1.2
Specific Gravity
2.86-2.992.5-2.7
0
8.4
👆🏻
Transparency
Translucent
Translucent to Opaque
Density
2.8-2.9 g/cm32.6-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.70 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
-
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
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
-
-
Deposits in Western Continents
North America
USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Colombia, Paraguay
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria