Nephelinite and Pegmatite
Definition
Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
History
Origin
Brazil
Unknown
Discoverer
Unknown
R. J. Hauy
Etymology
from French néphéline, from Greek nephelē
From Greek pegma, pegmat which means- thing joined together + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Texture
Aphanitic
Pegmatitic
Color
Black, Brown, Colourless, Green, Grey, White
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
Yes
Yes
Wind Resistant
Yes
No
Acid Resistant
Yes
No
Appearance
Skeletal
Layered, Banded, Veined and Shiny
Uses
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
Types
Types
Peralkaline Nephelinite
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Features
Host Rock for Lead
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Used
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Used
Fossils
Absent
Absent
Formation
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.
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Composition
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Compound Content
Ca, CaO, Carbon, Cl, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Transformation
Metamorphism
Yes
Yes
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Properties
Physical Properties
Hardness
6.5
7
Grain Size
Fine Grained
Medium to Coarse Grained
Fracture
Flat
Conchoidal
Streak
White
White
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Grainy, Pearly and Vitreous
Compressive Strength
35.00 N/mm2
29
178.54 N/mm2
12
Cleavage
Imperfect
Perfect
Toughness
2.7
2.1
Specific Gravity
2.4-2.9
2.6-2.63
Transparency
Opaque
Translucent to Opaque
Density
2.5-3 g/cm3
2.6-2.65 g/cm3
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K
13
Not Available
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Reserves
Deposits in Eastern Continents
Asia
Japan
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Africa
Rwanda, Tanzania
South Africa
Europe
Not Yet Found
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Colombia
Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, Queensland, South Australia, Western Australia
All about Nephelinite and Pegmatite Properties
Know all about Nephelinite and Pegmatite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Pegmatite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Pegmatite is Pegmatitic. Nephelinite appears Skeletal and Pegmatite appears Layered, Banded, Veined and Shiny. The luster of Nephelinite is vitreous to metallic while that of Pegmatite is grainy, pearly and vitreous. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz.
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