Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
Discoverer
Unknown
Alexandre Brongniart
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Amphibole + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Banded, Foliated, Massive
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black, Brown, Green, Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction Aggregate
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Rhomb Porphyry
Hornblendite
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Clasts are smooth to touch, Matrix variable, 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
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.
Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
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
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Not Registered
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Coarse Grained
Fracture
Irregular
Irregular to Conchoidal
Streak
White
White to Grey
Porosity
Less Porous
Less Porous
Luster
Dull
Vitreous to Dull
Cleavage
Imperfect
Irregular
Specific Gravity
2.5-4
2.5
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
2.85-3.07 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Russia, Turkey
Africa
Egypt, Ethiopia, Ghana, South Africa
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Germany, Greece, Iceland, Norway, Poland
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
South Australia, Western Australia
Porphyry vs Amphibolite 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 Amphibolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Amphibolite. Learn more about Porphyry vs Amphibolite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Amphibolite include Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Porphyry and Amphibolite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Amphibolite include As dimension stone, Building houses or walls, Cobblestones, Construction aggregate, For road aggregate, Landscaping, Production of glass and ceramics, Roadstone.
More about Porphyry and Amphibolite
Here you can know more about Porphyry and Amphibolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Amphibolite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Amphibolite includes Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Amphibolite, 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, Amphibolite is available in black, brown, green, grey colors. Appearance of Porphyry is Dull and that of Amphibolite is Foliated. Properties of rock is another aspect for Porphyry vs Amphibolite. Hardness of Porphyry and Amphibolite is 6-7. The types of Porphyry are Rhomb Porphyry whereas types of Amphibolite are Hornblendite. 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 Amphibolite is white to grey. The specific heat capacity of Porphyry is Not Available and that of Amphibolite is Not Available. 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 Amphibolite is heat resistant, pressure resistant, wear resistant.