Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Greek mulōn mill + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Foliated
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black to Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction Aggregate
for Road Aggregate, Landscaping, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Creating Artwork, Gemstone, Jewelry
Types
Rhomb Porphyry
Blastomylonites, Ultramylonites and Phyllonites
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Surfaces are often shiny
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.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Porphyroblasts
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
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, Sea Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Imperfect
Conchoidal
Toughness
1.7
Not Available
Specific Gravity
2.5-4
2.97-3.05
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
2.6-4.8 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
China, India, Indonesia, Saudi Arabia, South Korea
Africa
Egypt, Ethiopia, Ghana, South Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
Central Australia, Western Australia
Porphyry vs Mylonite 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 Mylonite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Mylonite. Learn more about Porphyry vs Mylonite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Mylonite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Porphyry and Mylonite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Mylonite include For road aggregate, Landscaping, Roadstone.
More about Porphyry and Mylonite
Here you can know more about Porphyry and Mylonite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Mylonite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Mylonite includes Porphyroblasts. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Mylonite, 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, Mylonite is available in black to grey colors. Appearance of Porphyry is Dull and that of Mylonite is Dull, Banded and Foilated. Properties of rock is another aspect for Porphyry vs Mylonite. The hardness of Porphyry is 6-7 and that of Mylonite is 3-4. The types of Porphyry are Rhomb Porphyry whereas types of Mylonite are Blastomylonites, Ultramylonites and Phyllonites. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Mylonite is white. The specific heat capacity of Porphyry is Not Available and that of Mylonite is 1.50 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 Mylonite is heat resistant, impact resistant, pressure resistant.