Definition
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
  
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
  
History
  
  
Origin
Unknown
  
Germany
  
Discoverer
Unknown
  
Christian Leopold von Buch
  
Etymology
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
  
From Greek di + base
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Granular
  
Aphanitic, Granular
  
Color
Brown, Buff, Cream, Green, Grey, Pink, White
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Banded and Foilated
  
Vesicular
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
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, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Creating Artwork
  
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
  
Types
Borolanite and Litchfieldite
  
Not Available
  
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
  
Smooth to touch
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Stonehenge in English county of Wiltshire
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
  
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
  
Composition
  
  
Mineral Content
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
  
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering, Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion
  
Chemical Erosion, Coastal Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
5.5-6
  
7
  
Grain Size
Fine Grained
  
Fine to Medium Grained
  
Fracture
Conchoidal to Uneven
  
Conchoidal
  
Streak
White
  
Black
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Greasy to Dull
  
Not Available
  
Compressive Strength
150.00 N/mm2
  
14
225.00 N/mm2
  
7
Cleavage
Poor
  
Not Available
  
Toughness
Not Available
  
1.6
  
Specific Gravity
2.6
  
2.86-2.87
  
Transparency
Translucent to Opaque
  
Opaque
  
Density
2.6 g/cm3
  
2.7-3.3 g/cm3
  
Thermal Properties
  
  
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
  
India
  
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
  
South Africa, Tanzania
  
Europe
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Greenland
  
Antarctica, Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil, Chile, Colombia, Uruguay, Venezuela
  
Argentina, Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
  
Central Australia, New Zealand, Queensland, Western Australia