Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Origin
Egypt
North America
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Andes mountains, where it is found in abundance
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Aphanitic to Porphyritic
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull and Soft
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
Garden Decoration, Paving Stone
Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction Aggregate
Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Commemorative Tablets, Creating Artwork
Types
Rhomb Porphyry
Icelandite
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Generally rough to touch, High silica content, Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Middle of the Earth in Ecuador
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not 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.
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Not Registered
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Irregular
Uneven
Porosity
Less Porous
Less Porous
Compressive Strength
Not Available
Cleavage
Imperfect
Not Available
Specific Gravity
2.5-4
2.5-2.8
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
2.11-2.36 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
India, Indonesia, Japan, Nepal, South Korea
Africa
Egypt, Ethiopia, Ghana, South Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Mexico, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New South Wales, New Zealand, Western Australia
Porphyry vs Andesite 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 Andesite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Andesite. Learn more about Porphyry vs Andesite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Andesite include Decorative aggregates, Floor tiles, Homes, Interior decoration and Kitchens. Due to some exceptional properties of Porphyry and Andesite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Andesite include Cobblestones, Construction aggregate, For road aggregate.
More about Porphyry and Andesite
Here you can know more about Porphyry and Andesite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Andesite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Andesite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Andesite, 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, Andesite is available in bluish - grey, grey, pink, yellow colors. Appearance of Porphyry is Dull and that of Andesite is Dull and Soft. Properties of rock is another aspect for Porphyry vs Andesite. The hardness of Porphyry is 6-7 and that of Andesite is 7. The types of Porphyry are Rhomb Porphyry whereas types of Andesite are Icelandite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Andesite is white. The specific heat capacity of Porphyry is Not Available and that of Andesite is 2.39 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 Andesite is heat resistant, pressure resistant, wear resistant.