Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
  
Claystone is a fine-grained, dark gray to pink sedimentary rock which mainly consists of compacted and hardened clay
  
History
  
  
Origin
Egypt
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
  
From English clay and stone as the rock contains more amount of clay
  
Class
Igneous Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Plutonic
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Clastic
  
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
  
Black, Blue, Brown, Green, Grey, Orange, Red, White, Yellow
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Dull
  
Rough and Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Entryways, Floor Tiles, Homes, Interior Decoration
  
Exterior Uses
Garden Decoration, Paving Stone
  
As Facing Stone, Roof Tiles
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Construction Aggregate
  
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone, Jewelry
  
Pottery
  
Types
Rhomb Porphyry
  
Not Available
  
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
  
Available in Lots of Colors and Patterns, Smooth to touch, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Present
  
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.
  
Claystone is generally quite soft, but can be hard and brittle. It forms due to weathering of mudstone.
  
Composition
  
  
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
  
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, Ca, NaCl, CaO, Iron(III) Oxide, MgO, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Not Registered
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Coastal Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6-7
  
3.5-4
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Irregular
  
Not Available
  
Streak
White
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Dull
  
Dull
  
Cleavage
Imperfect
  
Perfect
  
Toughness
1.7
  
2.6
  
Specific Gravity
2.5-4
  
0
  
Transparency
Translucent to Opaque
  
Opaque
  
Density
2.5-2.52 g/cm3
  
2-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
  
Bangladesh, China, India, Russia
  
Africa
Egypt, Ethiopia, Ghana, South Africa
  
Ethiopia, Kenya, Morocco, South Africa, Tanzania
  
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
  
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, Cuba, Jamaica, USA
  
Canada, Panama, USA
  
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
  
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand, Western Australia
  
New South Wales, New Zealand, Queensland, Victoria, Western Australia
  
Porphyry vs Claystone 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 Claystone characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Claystone. Learn more about Porphyry vs Claystone in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Claystone include Decorative aggregates, Entryways, Floor tiles, Homes and Interior decoration. Due to some exceptional properties of Porphyry and Claystone, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Claystone include As a sintering agent in steel industry to process iron ore, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar.
More about Porphyry and Claystone
Here you can know more about Porphyry and Claystone. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Claystone consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Claystone includes Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Claystone, 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, Claystone is available in black, blue, brown, green, grey, orange, red, white, yellow colors. Appearance of Porphyry is Dull and that of Claystone is Rough and Dull. Properties of rock is another aspect for Porphyry vs Claystone. The hardness of Porphyry is 6-7 and that of Claystone is 3.5-4. The types of Porphyry are Rhomb Porphyry whereas types of Claystone are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Claystone is white. The specific heat capacity of Porphyry is Not Available and that of Claystone 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 Claystone is heat resistant, impact resistant.