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
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
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Aphanitic, Granular
Color
Black, Brown, Green, Grey, Red, Rust, White
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Vesicular
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
Construction Industry
Construction Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
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
Dolerite
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Smooth to touch
Archaeological Significance
Famous Monuments
-
Stonehenge in English county of Wiltshire
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.
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Fine to Medium Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Highly Porous
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
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, 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 Dolerite. 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 0.71 kJ/Kg K and that of Diabase is 0.84 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 Diabase is heat resistant, impact resistant, pressure resistant, wear resistant.