Definition
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
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
Discoverer
Unknown
Unknown
Etymology
From the mineral feldspathoid which is the main content of rock
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
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
Black, Brown, Green, Grey, Pink, White
Black, Brown, Pink, Red, White
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, 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
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone
Medical Industry
Taken as a Supplement for Calcium or Magnesium
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Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Igneous rock
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Host Rock for Lead
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Famous Monuments
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Konark Sun Temple in India, Washington Monument, US
Formation
Foidolites 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.
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.
Mineral Content
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Impact Metamorphism
Types of Weathering
-
Biological Weathering, Mechanical Weathering
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Sea Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Dull
Specific Gravity
2.86
2.5-2.7
Transparency
Translucent
Translucent to Opaque
Density
-9999 g/cm3
2.6-2.9 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
South Africa, Western Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
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Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
-
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria
Foidolite vs Gneiss 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. Foidolite vs Gneiss characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Foidolite and Properties of Gneiss. Learn more about Foidolite vs Gneiss in the next section. The interior uses of Foidolite include Decorative aggregates and Interior decoration whereas the interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Foidolite and Gneiss, they have various applications in construction industry. The uses of Foidolite in construction industry include As dimension stone, Cement manufacture, For road aggregate and that of Gneiss include As dimension stone.
More about Foidolite and Gneiss
Here you can know more about Foidolite and Gneiss. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Foidolite and Gneiss consists of mineral content and compound content. The mineral content of Foidolite includes Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene and mineral content of Gneiss includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Foidolite vs Gneiss, the texture, color and appearance plays an important role in determining the type of rock. Foidolite is available in black, brown, green, grey, pink, white colors whereas, Gneiss is available in black, brown, pink, red, white colors. Appearance of Foidolite is Dull and that of Gneiss is Foliated. Properties of rock is another aspect for Foidolite vs Gneiss. The hardness of Foidolite is 1.5 and that of Gneiss is 7. The types of Foidolite are Igneous rock whereas types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Foidolite and Gneiss is white. The specific heat capacity of Foidolite is 0.79 kJ/Kg K and that of Gneiss is 0.70 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Foidolite is heat resistant, wear resistant whereas Gneiss is heat resistant, pressure resistant, scratch resistant, wear resistant.