Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Dolomite is a sedimentary rock containing more than 50 percent of the mineral dolomite by weight
Origin
Egypt
Southern Alps, France
Discoverer
Unknown
Dolomieu
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From French, from the name of Dolomieu (1750–1801), the French geologist who discovered the rock
Class
Igneous Rocks
Sedimentary 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
Earthy
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Glassy or Pearly
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Construction Aggregate
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock
Medical Industry
Not Yet Used
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Jewellery, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Types
Rhomb Porphyry
Boninite and Jasperoid
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
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.
Dolomite rocks are originally deposited as calcite or aragonite rich limestone, but during diagenesis process, the calcite or aragonite is transformed into dolomite.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Clay Minerals, Pyrite, Quartz, Sulfides
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Not Registered
Not Applicable
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Not Applicable
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Less Porous
Luster
Dull
Vitreous and Pearly
Compressive Strength
Not Available
Cleavage
Imperfect
Perfect
Specific Gravity
2.5-4
2.8-3
Transparency
Translucent to Opaque
Transparent to Translucent
Density
2.5-2.52 g/cm3
2.8-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
China, India
Africa
Egypt, Ethiopia, Ghana, South Africa
Morocco, Namibia
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Austria, Italy, Romania, Spain, Switzerland
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Mexico, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Brazil, Colombia
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New South Wales, Queensland, Yorke Peninsula
Porphyry vs Dolomite 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 Dolomite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Dolomite. Learn more about Porphyry vs Dolomite in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Dolomite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Porphyry and Dolomite, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Dolomite include As a flux in the production of steel and pig iron, As a sintering agent in steel industry to process iron ore, As dimension stone, Cement manufacture, For road aggregate, Making natural cement, Manufacture of magnesium and dolomite refractories, Production of glass and ceramics, Serves as an oil and gas reservoir rock.
More about Porphyry and Dolomite
Here you can know more about Porphyry and Dolomite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Dolomite consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Dolomite includes Clay Minerals, Pyrite, Quartz, Sulfides. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Dolomite, 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, Dolomite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Porphyry is Dull and that of Dolomite is Glassy or Pearly. Properties of rock is another aspect for Porphyry vs Dolomite. The hardness of Porphyry is 6-7 and that of Dolomite is 3.5-4. The types of Porphyry are Rhomb Porphyry whereas types of Dolomite are Boninite and Jasperoid. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Dolomite is white. The specific heat capacity of Porphyry is Not Available and that of Dolomite 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 Dolomite is heat resistant, pressure resistant, wear resistant.