Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Origin
Pennsylvania, U.S.
Egypt
Discoverer
Unknown
Unknown
Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Porphyritic
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Brown, Green, Grey, Red, Rust, White
Durability
Durable
Durable
Appearance
Veined or Pebbled
Dull
Interior Uses
-
Decorative Aggregates, Interior Decoration
Exterior Uses
-
Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Construction Aggregate
Medical Industry
In Chemical and Pharmaceutical Industry, Manufacture of Aspirins
-
Antiquity Uses
-
Artifacts, Monuments, Sculpture
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Creating Artwork, Gemstone, Jewelry
Types
Semi-anthracite and Meta-anthracite
Rhomb Porphyry
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Archaeological Significance
Formation
Anthracite forms from the accumulation of plant debris in a swamp environment. When plant debris dies and falls into the swamp, the standing water of the swamp protects it from decay.
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.
Mineral Content
Calcite, Clay, Clay Minerals
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Irregular
Porosity
Less Porous
Less Porous
Specific Gravity
1.1-1.4
2.5-4
Transparency
Opaque
Translucent to Opaque
Density
1.25-2.5 g/cm3
2.5-2.52 g/cm3
Resistance
Heat Resistant, Water Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Egypt, Ethiopia, Ghana, South Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Cuba, Jamaica, USA
South America
Brazil, Chile, Colombia, Venezuela
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New South Wales, New Zealand, Western Australia
Anthracite vs Porphyry 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. Anthracite vs Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Anthracite and Properties of Porphyry. Learn more about Anthracite vs Porphyry in the next section. The interior uses of Anthracite include whereas the interior uses of Porphyry include Decorative aggregates and Interior decoration. Due to some exceptional properties of Anthracite and Porphyry, they have various applications in construction industry. The uses of Anthracite in construction industry include Cement manufacture, For road aggregate, Making natural cement, Steel production and that of Porphyry include Construction aggregate.
More about Anthracite and Porphyry
Here you can know more about Anthracite and Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Anthracite and Porphyry consists of mineral content and compound content. The mineral content of Anthracite includes Calcite, Clay, Clay Minerals and mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica. You can also check out the list of all Metamorphic Rocks. When we have to compare Anthracite vs Porphyry, the texture, color and appearance plays an important role in determining the type of rock. Anthracite is available in black, brown, dark brown, grey, light to dark grey colors whereas, Porphyry is available in black, brown, green, grey, red, rust, white colors. Appearance of Anthracite is Veined or Pebbled and that of Porphyry is Dull. Properties of rock is another aspect for Anthracite vs Porphyry. The hardness of Anthracite is 1-1.5 and that of Porphyry is 6-7. The types of Anthracite are Semi-anthracite and Meta-anthracite whereas types of Porphyry are Rhomb Porphyry. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Anthracite is black while that of Porphyry is white. The specific heat capacity of Anthracite is 1.32 kJ/Kg K and that of Porphyry is 0.71 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Anthracite is heat resistant, water resistant whereas Porphyry is heat resistant, impact resistant.