Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Litchfieldite is a rare igneous rock which is coarse-grained, foliated and a variety of nepheline syenite, sometimes also called as nepheline syenite gneiss or gneissic nepeheline syenite
Discoverer
Unknown
Bayley
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From its occurrence at Litchfield, Maine, USA
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Porphyritic
Granular
Color
Black, Brown, Green, Grey, Red, Rust, White
Brown, Buff, Cream, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Banded and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
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
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Gemstone, Jewelry
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
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.
Litchfieldite 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
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, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Irregular
Conchoidal to Uneven
Porosity
Less Porous
Less Porous
Luster
Dull
Greasy to Dull
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
-
Africa
Egypt, Ethiopia, Ghana, South Africa
South Africa
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Finland, Norway, Portugal
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
-
Porphyry vs Litchfieldite 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 Litchfieldite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Litchfieldite. Learn more about Porphyry vs Litchfieldite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Litchfieldite include Countertops, Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Porphyry and Litchfieldite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Litchfieldite 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 Litchfieldite
Here you can know more about Porphyry and Litchfieldite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Litchfieldite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Litchfieldite 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 Litchfieldite, the texture, color and appearance plays an important role in determining the type of rock. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas, Litchfieldite is available in brown, buff, cream, green, grey, pink, white colors. Appearance of Porphyry is Dull and that of Litchfieldite is Banded and Foilated. Properties of rock is another aspect for Porphyry vs Litchfieldite. The hardness of Porphyry is 6-7 and that of Litchfieldite is 5.5-6. The types of Porphyry are Rhomb Porphyry whereas types of Litchfieldite 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 Litchfieldite is white. The specific heat capacity of Porphyry is 0.71 kJ/Kg K and that of Litchfieldite is 0.79 kJ/Kg K. 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 Litchfieldite is heat resistant, impact resistant, wear resistant.