Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From English feldspar and -ite
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
Arborescent Patterned, Vitreous
Color
Black, Brown, Green, Grey, Red, Rust, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction Aggregate
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Mirror, Jewelry
Types
Rhomb Porphyry
Igneous rock
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock
Archaeological Significance
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.
Felsite 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
Feldspar, Iron Oxides
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
Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Glacier Erosion, Water Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Very Less Porous
Specific Gravity
2.5-4
2.6-2.7
Transparency
Translucent to Opaque
Translucent
Density
2.5-2.52 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Afghanistan, Indonesia, Japan, Russia
Africa
Egypt, Ethiopia, Ghana, South Africa
Kenya
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada, Mexico, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New Zealand
Porphyry vs Felsite 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 Felsite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Felsite. Learn more about Porphyry vs Felsite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Felsite include Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Porphyry and Felsite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Felsite include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Porphyry and Felsite
Here you can know more about Porphyry and Felsite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Felsite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Felsite includes Feldspar, Iron Oxides. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Felsite, the texture, color and appearance plays an important role in determining the type of rock. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas, Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Porphyry is Dull and that of Felsite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Porphyry vs Felsite. The hardness of Porphyry is 6-7 and that of Felsite is 5-5.5. The types of Porphyry are Rhomb Porphyry whereas types of Felsite are Igneous rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Felsite is white. The specific heat capacity of Porphyry is 0.71 kJ/Kg K and that of Felsite 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 Felsite is heat resistant, impact resistant.