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
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Brown, Green, Grey, White
Black, Brown, 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
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
Cataclastic rock
Features
Host Rock for Lead
Host Rock for Lead
Archaeological Significance
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
-
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
-
Grain Size
Fine Grained
Very fine-grained
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Vitreous
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
-
Great Britain, Switzerland
Deposits in Western Continents
North America
Canada, USA
-
Deposits in Oceania Continent
Australia
-
Central Australia, Western Australia
All about Nephelinite and Pseudotachylite Properties
Know all about Nephelinite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Nephelinite is Aphanitic whereas that of Pseudotachylite is Quench. Nephelinite appears Skeletal and Pseudotachylite appears Dull and Soft. The luster of Nephelinite is vitreous to metallic while that of Pseudotachylite is vitreous. Nephelinite is available in black, brown, green, grey, white colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Pseudotachylite are creating artwork, gemstone.