Definition
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.
Origin
Unknown
Tonale, Italy
Discoverer
Unknown
Unknown
Etymology
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
Not Available
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Granular
Phaneritic
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Black, Brown, Light to Dark Grey, White
Durability
Durable
Durable
Appearance
Banded and Foilated
Banded and Foilated
Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
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
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, Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Creating Artwork
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
Is one of the oldest rock, Typically speckled black and white.
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Formation
Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.
Mineral Content
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
NaCl, CaO, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal to Uneven
Conchoidal
Streak
White
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Greasy to Dull
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Poor
Not Available
Toughness
Not Available
2.1
Specific Gravity
2.6
2.86-3
Transparency
Translucent to Opaque
Opaque
Density
2.6 g/cm3
2.73 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Not Yet Found
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Egypt
Europe
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Finland, Germany, Italy, Romania, Sweden, Turkey
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil, Chile, Colombia, Uruguay, Venezuela
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
New Zealand, South Australia, Western Australia