Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Brown, Colourless, Green, Grey, White
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Dull and Soft
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Creating Artwork, Gemstone
Types
Peralkaline Nephelinite
Not Available
Features
Host Rock for Lead
Host Rock for Lead
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Not Yet Used
Formation
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Ca, CaO, Carbon, Cl, MgO
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Not Applicable
Grain Size
Fine Grained
Very fine-grained
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Vitreous
Cleavage
Imperfect
Irregular
Toughness
2.7
Not Available
Specific Gravity
2.4-2.9
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
2.5-3 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
Western Africa
Europe
Not Yet Found
Great Britain, Switzerland
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Not Yet Found
South America
Colombia
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, Western Australia
Nephelinite vs Pseudotachylite 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. Nephelinite vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Nephelinite and Properties of Pseudotachylite. Learn more about Nephelinite vs Pseudotachylite in the next section. The interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Nephelinite and Pseudotachylite, they have various applications in construction industry. The uses of Nephelinite in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Nephelinite and Pseudotachylite
Here you can know more about Nephelinite and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Nephelinite and Pseudotachylite consists of mineral content and compound content. The mineral content of Nephelinite includes Clinopyroxene, Nepheline, Plagioclase and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all . When we have to compare Nephelinite vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas, Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Nephelinite is Skeletal and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Nephelinite vs Pseudotachylite. The hardness of Nephelinite is 6.5 and that of Pseudotachylite is 7. The types of Nephelinite are Peralkaline Nephelinite whereas types of Pseudotachylite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Nephelinite is white while that of Pseudotachylite is light to dark brown. The specific heat capacity of Nephelinite is 0.88 kJ/Kg K and that of Pseudotachylite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Nephelinite is heat resistant whereas Pseudotachylite is heat resistant.