Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
  
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
  
History
  
  
Origin
Brazil
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
from French néphéline, from Greek nephelē
  
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Aphanitic
  
Vesicular
  
Color
Black, Brown, Colourless, Green, Grey, White
  
Black, Brown, Dark Grey to Black, Red
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Skeletal
  
Glassy and Vesicular
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
  
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
  
Types
Peralkaline Nephelinite
  
Not Available
  
Features
Host Rock for Lead
  
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
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.
  
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
  
Composition
  
  
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
  
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
  
Compound Content
Ca, CaO, Carbon, Cl, MgO
  
Ca, NaCl
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
  
Physical Properties
  
  
Hardness
6.5
  
5-6
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Flat
  
Conchoidal
  
Streak
White
  
White
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Vitreous to Metallic
  
Subvitreous to Dull
  
Compressive Strength
35.00 N/mm
2
  
29
Not Available
  
Cleavage
Imperfect
  
Perfect
  
Toughness
2.7
  
2.1
  
Specific Gravity
2.4-2.9
  
Not Available
  
Transparency
Opaque
  
Opaque
  
Density
2.5-3 g/cm3
  
Not Available
  
Thermal Properties
  
  
Specific Heat Capacity
0.88 kJ/Kg K
  
13
Not Available
  
Resistance
Heat Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Japan
  
Afghanistan, Indonesia, Japan, Russia
  
Africa
Rwanda, Tanzania
  
Ethiopia, Kenya, Tanzania
  
Europe
Not Yet Found
  
Greece, Hungary, Iceland, Italy, Turkey
  
Others
Hawaii Islands
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
  
South America
Colombia
  
Argentina, Chile, Ecuador, Peru
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New Zealand, Western Australia