Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Trachyandesite is an extrusive igneous rock.
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
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
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull and Soft
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Homes, 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
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Creating Artwork, Pottery
Types
Rhomb Porphyry
Basaltic Trachyandesite
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
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.
Trachyandesite 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
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
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
Cataclastic Metamorphism, Contact 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, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Irregular
Conchoidal
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Compressive Strength
Not Available
Cleavage
Imperfect
Perfect
Specific Gravity
2.5-4
2.8-3
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
2.9-3.1 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, Russia
Africa
Egypt, Ethiopia, Ghana, South Africa
South Africa
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Iceland
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
Not Yet Found
Porphyry vs Trachyandesite 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 Trachyandesite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Trachyandesite. Learn more about Porphyry vs Trachyandesite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Trachyandesite include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Porphyry and Trachyandesite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Trachyandesite include Building houses or walls, Cobblestones, For road aggregate, Rail track ballast, Roadstone.
More about Porphyry and Trachyandesite
Here you can know more about Porphyry and Trachyandesite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Trachyandesite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Trachyandesite includes Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Trachyandesite, 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, Trachyandesite is available in black, brown, light to dark grey colors. Appearance of Porphyry is Dull and that of Trachyandesite is Dull and Soft. Properties of rock is another aspect for Porphyry vs Trachyandesite. The hardness of Porphyry is 6-7 and that of Trachyandesite is 4-5. The types of Porphyry are Rhomb Porphyry whereas types of Trachyandesite are Basaltic Trachyandesite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry is white while that of Trachyandesite is light to dark brown. The specific heat capacity of Porphyry is Not Available and that of Trachyandesite is 0.84 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 Trachyandesite is heat resistant, pressure resistant, wear resistant.