Anorthosite and Porphyry
Definition
Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
History
Origin
Unknown
Egypt
Discoverer
Unknown
Unknown
Etymology
From French anorthose plagioclase + -ite1
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Plutonic
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Texture
Foliated, Glassy
Porphyritic
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
No
Scratch Resistant
No
Yes
Stain Resistant
No
Yes
Wind Resistant
Yes
No
Acid Resistant
No
Yes
Appearance
Layered, Banded, Veined and Shiny
Dull
Uses
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Construction Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Creating Artwork, Curling
Creating Artwork, Gemstone, Jewelry
Types
Types
Proterozoic Anorthosite and Archean Anorthosite
Rhomb Porphyry
Features
Generally rough to touch, Is one of the oldest rock
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Used
Fossils
Absent
Absent
Formation
Formation
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
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.
Composition
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
Yes
Yes
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Not Registered
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Properties
Physical Properties
Hardness
5-6
6-7
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Irregular
Streak
White
White
Porosity
Less Porous
Less Porous
Luster
Pearly to Subvitreous
Dull
Cleavage
Irregular
Imperfect
Toughness
Not Available
1.7
Specific Gravity
2.62-2.82
2.5-4
Transparency
Translucent
Translucent to Opaque
Density
2.7-4 g/cm3
2.5-2.52 g/cm3
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K
15
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Reserves
Deposits in Eastern Continents
Asia
Not Yet Found
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Africa
Not Yet Found
Egypt, Ethiopia, Ghana, South Africa
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada
Canada, Cuba, Jamaica, USA
South America
Bolivia, Colombia
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
New South Wales, New Zealand, Western Australia
All about Anorthosite and Porphyry Properties
Know all about Anorthosite and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Anorthosite and Porphyry belong to Igneous Rocks.Texture of Anorthosite is Foliated, Glassy whereas that of Porphyry is Porphyritic. Anorthosite appears Layered, Banded, Veined and Shiny and Porphyry appears Dull. The luster of Anorthosite is pearly to subvitreous while that of Porphyry is dull. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors whereas Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. The commercial uses of Anorthosite are creating artwork, curling and that of Porphyry are creating artwork, gemstone, jewelry.
|
||
|
||
|
