Definition
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
  
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
  
History
  
  
Origin
Unknown
  
Egypt
  
Discoverer
Unknown
  
Unknown
  
Etymology
From English feldspar and -ite
  
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Volcanic
  
Plutonic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Arborescent Patterned, Vitreous
  
Porphyritic
  
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
  
Black, Brown, Colourless, Green, Grey, Red, Rust, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Layered, Banded, Veined and Shiny
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Flooring, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
Paving Stone, Garden Decoration
  
Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
  
Construction Aggregate
  
Medical Industry
Surgery
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Mirror, Jewelry
  
Creating Artwork, Gemstone, Jewelry
  
Types
Not Available
  
Rhomb Porphyry
  
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock
  
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
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.
  
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.
  
Composition
  
  
Mineral Content
Feldspar, Iron Oxides
  
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Not Registered
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Glacier Erosion, Water Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
5-5.5
  
6-7
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Irregular
  
Streak
White
  
White
  
Porosity
Very Less Porous
  
Less Porous
  
Luster
Vitreous
  
Dull
  
Compressive Strength
Not Available
  
Cleavage
Non-Existent
  
Imperfect
  
Toughness
Not Available
  
1.7
  
Specific Gravity
2.6-2.7
  
2.5-4
  
Transparency
Translucent
  
Translucent to Opaque
  
Density
2.6 g/cm3
  
2.5-2.52 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
Afghanistan, Indonesia, Japan, Russia
  
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
  
Africa
Kenya
  
Egypt, Ethiopia, Ghana, South Africa
  
Europe
Greece, Hungary, Iceland, Italy, Turkey
  
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, Mexico, USA
  
Canada, Cuba, Jamaica, USA
  
South America
Argentina, Chile, Ecuador, Peru
  
Bolivia, Brazil, Colombia, Ecuador, Paraguay
  
Deposits in Oceania Continent
  
  
Australia
New Zealand
  
New South Wales, New Zealand, Western Australia
  
Felsite vs Porphyry 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. Felsite vs Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Felsite and Properties of Porphyry. Learn more about Felsite vs Porphyry in the next section. The interior uses of Felsite include Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Porphyry include Decorative aggregates and Interior decoration. Due to some exceptional properties of Felsite and Porphyry, they have various applications in construction industry. The uses of Felsite in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Porphyry include Construction aggregate.
More about Felsite and Porphyry
Here you can know more about Felsite and Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Felsite and Porphyry consists of mineral content and compound content. The mineral content of Felsite includes Feldspar, Iron Oxides and mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica. You can also check out the list of all Igneous Rocks. When we have to compare Felsite vs Porphyry, the texture, color and appearance plays an important role in determining the type of rock. Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors whereas, Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. Appearance of Felsite is Layered, Banded, Veined and Shiny and that of Porphyry is Dull. Properties of rock is another aspect for Felsite vs Porphyry. The hardness of Felsite is 5-5.5 and that of Porphyry is 6-7. The types of Felsite are Not Available whereas types of Porphyry are Rhomb Porphyry. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Felsite and Porphyry is white. The specific heat capacity of Felsite is 0.92 kJ/Kg K and that of Porphyry is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Felsite is heat resistant, impact resistant whereas Porphyry is heat resistant, impact resistant.