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