Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Origin
Egypt
Pennsylvania, U.S.
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Greek anthrakites, from anthrax, anthrak meaning coal
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft 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
Amorphous, Glassy
Color
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull
Veined or Pebbled
Interior Uses
Decorative Aggregates, Interior Decoration
Not Yet Used
Exterior Uses
Garden Decoration, Paving Stone
Not Yet Used
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Construction Aggregate
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Medical Industry
Not Yet Used
In Chemical and Pharmaceutical Industry, Manufacture of Aspirins
Antiquity Uses
Artifacts, Monuments, Sculpture
Not Yet Used
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Types
Rhomb Porphyry
Semi-anthracite and Meta-anthracite
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Used
Not Yet 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.
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.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Calcite, Clay, Clay Minerals
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Contact Metamorphism, Regional 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
Cleavage
Imperfect
Non-Existent
Toughness
1.7
Not Available
Specific Gravity
2.5-4
1.1-1.4
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
1.25-2.5 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Water Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
Egypt, Ethiopia, Ghana, South Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada, Mexico, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Brazil, Chile, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New South Wales, Queensland, Victoria
All about Porphyry and Anthracite Properties
Know all about Porphyry and Anthracite properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry belongs to Igneous Rocks while Anthracite belongs to Metamorphic Rocks.Texture of Porphyry is Porphyritic whereas that of Anthracite is Amorphous, Glassy. Porphyry appears Dull and Anthracite appears Veined or Pebbled. The luster of Porphyry is dull while that of Anthracite is shiny. Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors whereas Anthracite is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Anthracite are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry.