Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
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
Porphyritic
Granular
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Brown, Buff, Cream, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull
Banded and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction 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
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Creating Artwork
Types
Rhomb Porphyry
Borolanite and Litchfieldite
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
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
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Formation
Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.
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
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, 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, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Not Registered
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Irregular
Conchoidal to Uneven
Porosity
Less Porous
Less Porous
Luster
Dull
Greasy to Dull
Compressive Strength
Not Available
Toughness
1.7
Not Available
Specific Gravity
2.5-4
2.6
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.5-2.52 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Africa
Egypt, Ethiopia, Ghana, South Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
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
Porphyry vs Nepheline Syenite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Porphyry vs Nepheline Syenite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Nepheline Syenite. Learn more about Porphyry vs Nepheline Syenite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Nepheline Syenite include Countertops, Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Porphyry and Nepheline Syenite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Nepheline Syenite include 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.
More about Porphyry and Nepheline Syenite
Here you can know more about Porphyry and Nepheline Syenite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Nepheline Syenite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Nepheline Syenite includes Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Nepheline Syenite, the texture, color and appearance plays an important role in determining the type of rock. Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors whereas, Nepheline Syenite is available in brown, buff, cream, green, grey, pink, white colors. Appearance of Porphyry is Dull and that of Nepheline Syenite is Banded and Foilated. Properties of rock is another aspect for Porphyry vs Nepheline Syenite. The hardness of Porphyry is 6-7 and that of Nepheline Syenite is 5.5-6. The types of Porphyry are Rhomb Porphyry whereas types of Nepheline Syenite are Borolanite and Litchfieldite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Nepheline Syenite is white. The specific heat capacity of Porphyry is Not Available and that of Nepheline Syenite is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Porphyry is heat resistant, impact resistant whereas Nepheline Syenite is heat resistant, impact resistant, wear resistant.