Definition
Borolanite is a variety of Nepheline Syenite and belongs to igneous rocks and contains nepheline-alkali feldspar pseudomorphs which occur as conspicuous white spots in the dark rock matrix
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Discoverer
Unknown
Unknown
Etymology
From Alkalic Igneous complex near Loch Borralan in northwest Scotland
from French néphéline, from Greek nephelē
Class
Igneous 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
Granular
Aphanitic
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Appearance
Banded and Foilated
Skeletal
Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
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Peralkaline Nephelinite
Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Formation
Borolanites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction 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
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
Regional Metamorphism
Contact Metamorphism
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Wind Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal to Uneven
Flat
Porosity
Less Porous
Less Porous
Luster
Greasy to Dull
Vitreous to Metallic
Specific Gravity
2.6
2.4-2.9
Transparency
Translucent to Opaque
Opaque
Density
2.6 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Japan
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Rwanda, Tanzania
Europe
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
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Others
Greenland
Hawaii Islands
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Chile, Colombia, Uruguay, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
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