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
Icelandite belongs to volcanic igneous rocks which is rich in iron and belongs to andesite rock
Discoverer
Unknown
Ian S. E. Carmichael
Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
From its origin place near Cenozoic volcano near the parsonage Þingmúli in East Iceland
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Not Applicable
Volcanic
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Foliated, Platy
Aphanitic to Porphyritic
Color
Black, Brown, Pink, Red, White
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Jewellery, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Cemetery Markers, Creating Artwork
Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Not Available
Features
Generally rough to touch, Is one of the oldest rock
Generally rough to touch, High silica content, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Konark Sun Temple in India, Washington Monument, US
Not Applicable
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Used
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.
Icelandite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Types of Metamorphism
Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Coarse Grained
Very fine-grained
Fracture
Irregular
Uneven
Porosity
Very Less Porous
Less Porous
Compressive Strength
Not Available
Cleavage
Poor
Not Available
Specific Gravity
2.5-2.7
2.5-2.8
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.9 g/cm3
2.11-2.36 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
India, Indonesia, Japan, Nepal, South Korea
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
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, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Mexico, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria
New South Wales, New Zealand, Western Australia
Gneiss vs Icelandite 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 Icelandite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Icelandite. Learn more about Gneiss vs Icelandite in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Icelandite include Decorative aggregates, Floor tiles, Homes, Interior decoration and Kitchens. Due to some exceptional properties of Gneiss and Icelandite, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Icelandite include Cobblestones, Construction aggregate, For road aggregate.
More about Gneiss and Icelandite
Here you can know more about Gneiss and Icelandite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Icelandite 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 Icelandite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Icelandite, 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, Icelandite is available in bluish - grey, grey, pink, yellow colors. Appearance of Gneiss is Foliated and that of Icelandite is Dull and Soft. Properties of rock is another aspect for Gneiss vs Icelandite. Hardness of Gneiss and Icelandite is 7. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Icelandite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss and Icelandite is white. The specific heat capacity of Gneiss is Not Available and that of Icelandite is 2.39 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 Icelandite is heat resistant, pressure resistant, scratch resistant, wear resistant.