Definition
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Origin
New Zealand
Brazil
Discoverer
Unknown
Unknown
Etymology
From Greek mulōn mill + -ite
from French néphéline, from Greek nephelē
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Aphanitic
Color
Black to Grey
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Skeletal
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Landscaping, Roadstone
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Blastomylonites, Ultramylonites and Phyllonites
Peralkaline Nephelinite
Features
Surfaces are often shiny
Host Rock for Lead
Archaeological Significance
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
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
Porphyroblasts
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
-
Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Porosity
Highly Porous
Less Porous
Luster
Shiny
Vitreous to Metallic
Specific Gravity
2.97-3.05
2.4-2.9
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
Japan
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Rwanda, Tanzania
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
-
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-
Mylonite 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. Mylonite vs Nephelinite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Mylonite and Properties of Nephelinite. Learn more about Mylonite vs Nephelinite in the next section. The interior uses of Mylonite include Decorative aggregates and Interior decoration whereas the interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Mylonite and Nephelinite, they have various applications in construction industry. The uses of Mylonite in construction industry include For road aggregate, Landscaping, Roadstone and that of Nephelinite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate.
More about Mylonite and Nephelinite
Here you can know more about Mylonite and Nephelinite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Mylonite and Nephelinite consists of mineral content and compound content. The mineral content of Mylonite includes Porphyroblasts 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 Mylonite vs Nephelinite, the texture, color and appearance plays an important role in determining the type of rock. Mylonite is available in black to grey colors whereas, Nephelinite is available in black, brown, green, grey, white colors. Appearance of Mylonite is Dull, Banded and Foilated and that of Nephelinite is Skeletal. Properties of rock is another aspect for Mylonite vs Nephelinite. The hardness of Mylonite is 3-4 and that of Nephelinite is 6.5. The types of Mylonite are Blastomylonites, Ultramylonites and Phyllonites 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 Mylonite and Nephelinite is white. The specific heat capacity of Mylonite is 1.50 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.Mylonite is heat resistant, impact resistant, pressure resistant whereas Nephelinite is heat resistant.