Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Origin
Brazil
New Zealand
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From Greek mulōn mill + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Foliated
Color
Black, Brown, Colourless, Green, Grey, White
Black to Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
for Road Aggregate, Landscaping, Roadstone
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, Jewelry
Types
Peralkaline Nephelinite
Blastomylonites, Ultramylonites and Phyllonites
Features
Host Rock for Lead
Surfaces are often shiny
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
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.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Porphyroblasts
Compound Content
Ca, CaO, Carbon, Cl, MgO
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Types of Metamorphism
Contact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
Shiny
Cleavage
Imperfect
Conchoidal
Toughness
2.7
Not Available
Specific Gravity
2.4-2.9
2.97-3.05
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
2.6-4.8 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Japan
China, India, Indonesia, Saudi Arabia, South Korea
Africa
Rwanda, Tanzania
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Not Yet Found
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, Western Australia
All about Nephelinite and Mylonite Properties
Know all about Nephelinite and Mylonite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Mylonite belongs to Metamorphic Rocks.Texture of Nephelinite is Aphanitic whereas that of Mylonite is Foliated. Nephelinite appears Skeletal and Mylonite appears Dull, Banded and Foilated. The luster of Nephelinite is vitreous to metallic while that of Mylonite is shiny. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Mylonite is available in black to grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Mylonite are creating artwork, gemstone, jewelry.