Definition
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
Trachyandesite is an extrusive igneous rock.
Discoverer
Unknown
Unknown
Etymology
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Banded and Foilated
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
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
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Pottery
Types
Borolanite and Litchfieldite
Basaltic Trachyandesite
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
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Famous Sculptures
Data Not Available
Data Not Available
Formation
Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Trachyandesite 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
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Cataclastic Metamorphism, Contact 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, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal to Uneven
Conchoidal
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Greasy to Dull
Earthy
Toughness
Not Available
2.3
Specific Gravity
2.6
2.8-3
Transparency
Translucent to Opaque
Opaque
Density
2.6 g/cm3
2.9-3.1 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
India, Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
South Africa
Europe
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Iceland
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Chile, Colombia, Uruguay, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
Not Yet Found