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
  
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
  
History
  
  
Origin
Unknown
  
Brazil
  
Discoverer
Unknown
  
Unknown
  
Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
  
from French néphéline, from Greek nephelē
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Banded, Foliated, Platy
  
Aphanitic
  
Color
Black, Brown, Pink, Red, White
  
Black, Brown, Colourless, Green, Grey, White
  
Maintenance
More
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
No
  
Yes
  
Appearance
Foliated
  
Skeletal
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
  
Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone
  
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
  
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
  
Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
  
Peralkaline Nephelinite
  
Features
Generally rough to touch, Is one of the oldest rock
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Konark Sun Temple in India, Washington Monument, US
  
Data Not Available
  
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
  
Fossils
Absent
  
Absent
  
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.
  
Nephelinite 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.
  
Composition
  
  
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
  
Clinopyroxene, Nepheline, Plagioclase
  
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Ca, CaO, Carbon, Cl, MgO
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Impact Metamorphism
  
Contact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
  
Chemical Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
7
  
6.5
  
Grain Size
Medium to Coarse Grained
  
Fine Grained
  
Fracture
Irregular
  
Flat
  
Streak
White
  
White
  
Porosity
Very Less Porous
  
Less Porous
  
Luster
Dull
  
Vitreous to Metallic
  
Compressive Strength
125.00 N/mm2
  
17
35.00 N/mm2
  
29
Cleavage
Poor
  
Imperfect
  
Toughness
1.2
  
2.7
  
Specific Gravity
2.5-2.7
  
2.4-2.9
  
Transparency
Translucent to Opaque
  
Opaque
  
Density
2.6-2.9 g/cm3
  
2.5-3 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.88 kJ/Kg K
  
13
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
  
Japan
  
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
  
Rwanda, 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
  
Not Yet Found
  
Others
Not Yet Found
  
Hawaii Islands
  
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
  
Not Yet Found
  
Gneiss vs Nephelinite 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 Nephelinite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Nephelinite. Learn more about Gneiss vs Nephelinite in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Gneiss and Nephelinite, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Nephelinite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate.
More about Gneiss and Nephelinite
Here you can know more about Gneiss and Nephelinite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Nephelinite 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 Nephelinite includes Clinopyroxene, Nepheline, Plagioclase. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Nephelinite, 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, Nephelinite is available in black, brown, colourless, green, grey, white colors. Appearance of Gneiss is Foliated and that of Nephelinite is Skeletal. Properties of rock is another aspect for Gneiss vs Nephelinite. The hardness of Gneiss is 7 and that of Nephelinite is 6.5. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Nephelinite are Peralkaline Nephelinite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss and Nephelinite is white. The specific heat capacity of Gneiss is Not Available and that of Nephelinite 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 Nephelinite is heat resistant.