Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.
Origin
Egypt
Tonale, Italy
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Not Available
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Phaneritic
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black, Brown, Light to Dark Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Banded and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction Aggregate
As Dimension Stone, Cement Manufacture, 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
Cemetery Markers, Creating Artwork
Types
Rhomb Porphyry
Not Available
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Is one of the oldest rock, Typically speckled black and white.
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
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.
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
NaCl, CaO, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact 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, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Irregular
Conchoidal
Streak
White
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Dull
Subvitreous to Dull
Cleavage
Imperfect
Not Available
Specific Gravity
2.5-4
2.86-3
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
2.73 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
Not Yet Found
Africa
Egypt, Ethiopia, Ghana, South Africa
Egypt
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Finland, Germany, Italy, Romania, Sweden, Turkey
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New Zealand, South Australia, Western Australia
Porphyry vs Trondhjemite 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 Trondhjemite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Trondhjemite. Learn more about Porphyry vs Trondhjemite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Trondhjemite include Decorative aggregates, Entryways, Flooring, Homes and Interior decoration. Due to some exceptional properties of Porphyry and Trondhjemite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Trondhjemite include As dimension stone, Cement manufacture, Cobblestones, Construction aggregate, For road aggregate.
More about Porphyry and Trondhjemite
Here you can know more about Porphyry and Trondhjemite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Trondhjemite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Trondhjemite includes Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Trondhjemite, 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, Trondhjemite is available in black, brown, light to dark grey, white colors. Appearance of Porphyry is Dull and that of Trondhjemite is Banded and Foilated. Properties of rock is another aspect for Porphyry vs Trondhjemite. Hardness of Porphyry and Trondhjemite is 6-7. The types of Porphyry are Rhomb Porphyry whereas types of Trondhjemite are Not Available. 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 Trondhjemite is bluish black. The specific heat capacity of Porphyry is Not Available and that of Trondhjemite is 0.92 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 Trondhjemite is heat resistant, pressure resistant, wear resistant.