Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Foliated, Platy
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Durability
Durable
Durable
Appearance
Dull
Layered and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Construction Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Used in aquariums, Writing Slates
Types
Rhomb Porphyry
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Easily splits into thin plates, Smooth to touch
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Used
Not Yet 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.
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
CaO, Carbon Dioxide, MgO
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
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Highly Porous
Specific Gravity
2.5-4
2.5-2.9
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Impact Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Africa
Egypt, Ethiopia, Ghana, South Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Brazil, Colombia, Guyana
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New South Wales, New Zealand, Queensland
Porphyry vs Schist 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 Schist characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Schist. Learn more about Porphyry vs Schist in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Schist include Decorative aggregates, Floor tiles and Interior decoration. Due to some exceptional properties of Porphyry and Schist, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Schist include As dimension stone, Building houses or walls, Cement manufacture, For road aggregate, Roadstone.
More about Porphyry and Schist
Here you can know more about Porphyry and Schist. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Schist consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Schist includes Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Schist, 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, Schist is available in black, blue, brown, dark brown, green, grey, silver colors. Appearance of Porphyry is Dull and that of Schist is Layered and Shiny. Properties of rock is another aspect for Porphyry vs Schist. The hardness of Porphyry is 6-7 and that of Schist is 3.5-4. The types of Porphyry are Rhomb Porphyry whereas types of Schist are Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Schist is white. The specific heat capacity of Porphyry is Not Available and that of Schist 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 Schist is impact resistant, pressure resistant, water resistant.