Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
  
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
  
History
  
  
Origin
Egypt
  
Germany
  
Discoverer
Unknown
  
Christian Leopold von Buch
  
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
  
From Greek di + base
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Aphanitic, Granular
  
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull
  
Vesicular
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
  
Exterior Uses
Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Construction Aggregate
  
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone, Jewelry
  
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
  
Types
Rhomb Porphyry
  
Not Available
  
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
  
Smooth to touch
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Stonehenge in English county of Wiltshire
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
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.
  
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
  
Composition
  
  
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
  
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Not Registered
  
Biological Weathering, Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Chemical Erosion, Coastal Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6-7
  
7
  
Grain Size
Fine Grained
  
Fine to Medium Grained
  
Fracture
Irregular
  
Conchoidal
  
Streak
White
  
Black
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Dull
  
Not Available
  
Compressive Strength
Not Available
  
225.00 N/mm
2
  
7
Cleavage
Imperfect
  
Not Available
  
Toughness
1.7
  
1.6
  
Specific Gravity
2.5-4
  
2.86-2.87
  
Transparency
Translucent to Opaque
  
Opaque
  
Density
2.5-2.52 g/cm3
  
2.7-3.3 g/cm3
  
Thermal Properties
  
  
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
  
India
  
Africa
Egypt, Ethiopia, Ghana, South Africa
  
South Africa, Tanzania
  
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Greenland
  
Antarctica, Greenland
  
Deposits in Western Continents
  
  
North America
Canada, Cuba, Jamaica, USA
  
Canada, USA
  
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
  
Argentina, Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand, Western Australia
  
Central Australia, New Zealand, Queensland, Western Australia
  
Porphyry vs Diabase 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 Diabase characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Diabase. Learn more about Porphyry vs Diabase in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Diabase include Countertops, Decorative aggregates, Homes, Interior decoration and Kitchens. Due to some exceptional properties of Porphyry and Diabase, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Diabase include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Porphyry and Diabase
Here you can know more about Porphyry and Diabase. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Diabase consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Diabase includes Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Diabase, 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, Diabase is available in dark grey to black colors. Appearance of Porphyry is Dull and that of Diabase is Vesicular. Properties of rock is another aspect for Porphyry vs Diabase. The hardness of Porphyry is 6-7 and that of Diabase is 7. The types of Porphyry are Rhomb Porphyry whereas types of Diabase are Not Available. 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 Diabase is black. The specific heat capacity of Porphyry is Not Available and that of Diabase 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 Diabase is heat resistant, impact resistant, pressure resistant, wear resistant.