Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Shoshonite is a basaltic rock, properly a potassic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass
Origin
Brazil
Wyoming,USA
Discoverer
Unknown
Iddings
Etymology
from French néphéline, from Greek nephelē
From the place of origin called Shoshone riverin Wyoming
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, Medium Grained Rock, Opaque Rock
Texture
Aphanitic
Porphyritic
Color
Black, Brown, Green, Grey, White
Brown- Black, Dark Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Sculpture
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Creating Artwork
Types
Peralkaline Nephelinite
Intermediate volcanic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Very fine grained rock
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.
Shoshonite 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
Clinopyroxene, Nepheline, Plagioclase
Pyroxene
Compound Content
Ca, CaO, Carbon, Cl, MgO
Aluminium Oxide, Iron(III) Oxide, Potassium Oxide, Sodium Oxide, Titanium Dioxide
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
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, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Streak
White
White to Grey
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Dull
Specific Gravity
2.4-2.9
2.98
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
2.9-3 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
South Africa
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Brazil
Deposits in Oceania Continent
All about Nephelinite and Shoshonite Properties
Know all about Nephelinite and Shoshonite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Shoshonite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Shoshonite is Porphyritic. Nephelinite appears Skeletal and Shoshonite appears Dull. The luster of Nephelinite is vitreous to metallic while that of Shoshonite is dull. Nephelinite is available in black, brown, green, grey, white colors whereas Shoshonite is available in brown- black, dark brown colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Shoshonite are cemetery markers, creating artwork.