Metapelite and Porphyry
Definition
Definition
Metapelite is an old and currently not widely used field geological term for a clay rich fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone
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 Pelos or clay in Greek
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Not Applicable
Plutonic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Texture
Foliated
Porphyritic
Color
Dark Greenish - Grey, Green, Light Green, Light Greenish Grey
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
No
Scratch Resistant
Yes
Yes
Stain Resistant
Yes
Yes
Wind Resistant
No
No
Acid Resistant
No
Yes
Appearance
Banded
Dull
Uses
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate
Construction Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone, Jewelry
Types
Types
Not Available
Rhomb Porphyry
Features
Easily splits into thin plates, It is One of the Oldest, Strongest and Hardest 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
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Used
Fossils
Absent
Absent
Formation
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Metapelite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
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
Albite, Chlorite, Quartz
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Compound Content
Aluminium Oxide, CaO, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
No
Yes
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Not Registered
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Properties
Physical Properties
Hardness
5-6
6-7
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Fibrous
Irregular
Streak
Unknown
White
Porosity
Highly Porous
Less Porous
Luster
Earthy
Dull
Cleavage
Not Available
Imperfect
Toughness
Not Available
1.7
Specific Gravity
3.4-3.7
2.5-4
Transparency
Opaque
Translucent to Opaque
Density
0-300 g/cm3
2.5-2.52 g/cm3
Thermal Properties
Specific Heat Capacity
0.72 kJ/Kg K
20
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Reserves
Deposits in Eastern Continents
Asia
Not Yet Found
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Africa
Western Africa
Egypt, Ethiopia, Ghana, South Africa
Europe
United Kingdom
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
Not Available
Canada, Cuba, Jamaica, USA
South America
Brazil, Colombia, Ecuador
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Western Australia
All about Metapelite and Porphyry Properties
Know all about Metapelite and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Metapelite belongs to Metamorphic Rocks while Porphyry belongs to Igneous Rocks.Texture of Metapelite is Foliated whereas that of Porphyry is Porphyritic. Metapelite appears Banded and Porphyry appears Dull. The luster of Metapelite is earthy while that of Porphyry is dull. Metapelite is available in dark greenish - grey, green, light green, light greenish grey colors whereas Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. The commercial uses of Metapelite are commemorative tablets, creating artwork and that of Porphyry are creating artwork, gemstone, jewelry.
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