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
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
Discoverer
Unknown
Unknown
Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
From 17th century, because of its greasy feel and use like a soap
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Foliated, Platy
Polished
Color
Black, Brown, Pink, Red, White
Black, Black to Grey, Green, Grey
Durability
Durable
Durable
Appearance
Foliated
Dull, Banded and Foilated
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Metamorphic rock
Features
Generally rough to touch, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
Konark Sun Temple in India, Washington Monument, US
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
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.
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
CaO, Mg, MgO
Types of Metamorphism
Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
-
Grain Size
Medium to Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Very Less Porous
Less Porous
Specific Gravity
2.5-2.7
2.86
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.9 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Europe
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria
Central Australia, New Zealand, Queensland
Gneiss vs Soapstone Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Gneiss vs Soapstone characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Soapstone. Learn more about Gneiss vs Soapstone in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Soapstone include Bathrooms, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Gneiss and Soapstone, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Soapstone include Manufacture of magnesium and dolomite refractories.
More about Gneiss and Soapstone
Here you can know more about Gneiss and Soapstone. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Soapstone consists of mineral content and compound content. The mineral content of Gneiss includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon and mineral content of Soapstone includes Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Soapstone, the texture, color and appearance plays an important role in determining the type of rock. Gneiss is available in black, brown, pink, red, white colors whereas, Soapstone is available in black, black to grey, green, grey colors. Appearance of Gneiss is Foliated and that of Soapstone is Dull, Banded and Foilated. Properties of rock is another aspect for Gneiss vs Soapstone. The hardness of Gneiss is 7 and that of Soapstone is 1. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Soapstone are Metamorphic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss is white while that of Soapstone is black. The specific heat capacity of Gneiss is 0.70 kJ/Kg K and that of Soapstone is 0.88 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Gneiss is heat resistant, pressure resistant, scratch resistant, wear resistant whereas Soapstone is heat resistant, pressure resistant.