Definition
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
Origin
North America
Unknown
Discoverer
Unknown
Unknown
Etymology
From Andes mountains, where it is found in abundance
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Granular
Color
Bluish - Grey, Grey, Pink, Yellow
Brown, Buff, Cream, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull and Soft
Banded and Foilated
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Office Buildings, Roof Tiles
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cobblestones, Construction Aggregate, for Road Aggregate
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
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork
Types
Icelandite
Borolanite and Litchfieldite
Features
Generally rough to touch, High silica content, Is one of the oldest rock
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
Archaeological Significance
Famous Monuments
Middle of the Earth in Ecuador
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Formation
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Compound Content
Silicon 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, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Uneven
Conchoidal to Uneven
Porosity
Less Porous
Less Porous
Luster
Vitreous
Greasy to Dull
Cleavage
Not Available
Poor
Toughness
1.1
Not Available
Specific Gravity
2.5-2.8
2.6
Transparency
Opaque
Translucent to Opaque
Density
2.11-2.36 g/cm3
2.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Indonesia, Japan, Nepal, South Korea
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Mexico, USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Chile, Colombia, Uruguay, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia