Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Minette is a variety of Lamprophyre and is porphyritic alkaline igneous rock which is mainly dominated by biotite and potassic feldspar
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From French mine ore, mine + ette
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Porphyritic
Color
Black, Brown, Colourless, Green, Grey, White
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, 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, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Types
Peralkaline Nephelinite
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite
Features
Host Rock for Lead
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, 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.
Minette formation takes place deep beneath the Earth’s surface at around 150 to 450 kms, and are erupted rapidly and violently.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
Compound Content
Ca, CaO, Carbon, Cl, MgO
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Wind Erosion
Grain Size
Fine Grained
Fine to Coarse Grained
Porosity
Less Porous
Very Less Porous
Luster
Vitreous to Metallic
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Imperfect
Conchoidal
Toughness
2.7
Not Available
Specific Gravity
2.4-2.9
2.86-2.87
Transparency
Opaque
Translucent to Opaque
Density
2.5-3 g/cm3
2.95-2.96 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
Angola, Botswana, Cameroon, Ethiopia, South Africa
Europe
Not Yet Found
England, Hungary, Iceland, United Kingdom
Others
Hawaii Islands
Antarctica, Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Colombia
Argentina, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, New Zealand, Queensland, South Australia, Western Australia
All about Nephelinite and Minette Properties
Know all about Nephelinite and Minette properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Minette belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Minette is Porphyritic. Nephelinite appears Skeletal and Minette appears Dull, Banded and Foilated. The luster of Nephelinite is vitreous to metallic while that of Minette is subvitreous to dull. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Minette is available in black, bluish - grey, brown, dark greenish - grey, green, grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Minette are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).