Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
  
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
  
History
  
  
Origin
Unknown
  
Egypt
  
Discoverer
Unknown
  
Unknown
  
Etymology
From French anorthose plagioclase + -ite1
  
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Plutonic
  
Plutonic
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Foliated, Glassy
  
Porphyritic
  
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
  
Black, Brown, Colourless, Green, Grey, Red, Rust, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Layered, Banded, Veined and Shiny
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
  
Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
  
Construction Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Curling
  
Creating Artwork, Gemstone, Jewelry
  
Types
Proterozoic Anorthosite and Archean Anorthosite
  
Rhomb Porphyry
  
Features
Generally rough to touch, Is one of the oldest rock
  
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
  
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.
  
Composition
  
  
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
  
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
  
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering
  
Biological Weathering, Chemical Weathering, Not Registered
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
5-6
  
6-7
  
Grain Size
Coarse Grained
  
Fine Grained
  
Fracture
Irregular
  
Irregular
  
Streak
White
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Pearly to Subvitreous
  
Dull
  
Cleavage
Irregular
  
Imperfect
  
Toughness
Not Available
  
1.7
  
Specific Gravity
2.62-2.82
  
2.5-4
  
Transparency
Translucent
  
Translucent to Opaque
  
Density
2.7-4 g/cm3
  
2.5-2.52 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.84 kJ/Kg K
  
15
Not Available
  
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
Not Yet Found
  
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
  
Africa
Not Yet Found
  
Egypt, Ethiopia, Ghana, South Africa
  
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
  
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada
  
Canada, Cuba, Jamaica, USA
  
South America
Bolivia, Colombia
  
Bolivia, Brazil, Colombia, Ecuador, Paraguay
  
Deposits in Oceania Continent
  
  
Australia
Central Australia, South Australia, Western Australia
  
New South Wales, New Zealand, Western Australia
  
Anorthosite vs Porphyry 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. Anorthosite vs Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Anorthosite and Properties of Porphyry. Learn more about Anorthosite vs Porphyry in the next section. The interior uses of Anorthosite include Decorative aggregates, Floor tiles, Homes and Interior decoration whereas the interior uses of Porphyry include Decorative aggregates and Interior decoration. Due to some exceptional properties of Anorthosite and Porphyry, they have various applications in construction industry. The uses of Anorthosite in construction industry include As dimension stone, Cement manufacture, For road aggregate and that of Porphyry include Construction aggregate.
More about Anorthosite and Porphyry
Here you can know more about Anorthosite and Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Anorthosite and Porphyry consists of mineral content and compound content. The mineral content of Anorthosite includes Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene and mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica. You can also check out the list of all Igneous Rocks. When we have to compare Anorthosite vs Porphyry, the texture, color and appearance plays an important role in determining the type of rock. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors whereas, Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. Appearance of Anorthosite is Layered, Banded, Veined and Shiny and that of Porphyry is Dull. Properties of rock is another aspect for Anorthosite vs Porphyry. The hardness of Anorthosite is 5-6 and that of Porphyry is 6-7. The types of Anorthosite are Proterozoic Anorthosite and Archean Anorthosite whereas types of Porphyry are Rhomb Porphyry. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Anorthosite and Porphyry is white. The specific heat capacity of Anorthosite is 0.84 kJ/Kg K and that of Porphyry is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Anorthosite is heat resistant, impact resistant, pressure resistant, scratch resistant, wear resistant whereas Porphyry is heat resistant, impact resistant.