Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Origin
Brazil
North America
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From Andes mountains, where it is found in abundance
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Aphanitic to Porphyritic
Color
Black, Brown, Colourless, Green, Grey, White
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Dull and Soft
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Commemorative Tablets, Creating Artwork
Types
Peralkaline Nephelinite
Icelandite
Features
Host Rock for Lead
Generally rough to touch, High silica content, Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Middle of the Earth in Ecuador
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not 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.
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Compound Content
Ca, CaO, Carbon, Cl, MgO
Silicon 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, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Very fine-grained
Porosity
Less Porous
Less Porous
Luster
Vitreous to Metallic
Vitreous
Cleavage
Imperfect
Not Available
Specific Gravity
2.4-2.9
2.5-2.8
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
2.11-2.36 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Japan
India, Indonesia, Japan, Nepal, South Korea
Africa
Rwanda, Tanzania
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Europe
Not Yet Found
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Mexico, USA
South America
Colombia
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, New Zealand, Western Australia