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Pumice and Porphyry


Porphyry and Pumice


Definition

Definition
Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals   
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix   

History
  
  

Origin
Spain   
Egypt   

Discoverer
Unknown   
Unknown   

Etymology
From Old French pomis, from a Latin dialect variant of pumex   
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
Volcanic   
Plutonic   

Other Categories
Fine Grained Rock, Opaque Rock   
Fine Grained Rock, Opaque Rock   

Texture

Texture
Vesicular   
Porphyritic   

Color
Beige, Colourless, Grey, Light Green, Light Grey, Pink, White, Yellow- 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
Yes   
Yes   

Appearance
Vesicular   
Dull   

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration   
Decorative Aggregates, Interior Decoration   

Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone   
Garden Decoration, Paving Stone   

Other Architectural Uses
Curbing, Powder   
Curbing   

Industry
  
  

Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, In landscaping and horticulture, Making natural cement, Production of lightweight concrete blocks   
Construction Aggregate   

Medical Industry
As an abrasive in skin exfoliating products, In Chemical and Pharmaceutical Industry, Medicines and Cosmetics   
Not Yet Used   

Antiquity Uses
Artifacts   
Artifacts, Monuments, Sculpture   

Other Uses
  
  

Commercial Uses
As a traction material on snow-covered roads, As an abrasive in pencil erasers, Fine abrasive used for polishing, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Used in aquariums   
Creating Artwork, Gemstone, Jewelry   

Types

Types
Scoria   
Rhomb Porphyry   

Features
Host Rock for Lead   
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
Pumice rock forms when the magma cools so quickly that atoms in the melt are not able to arrange themselves into a crystalline structure.   
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
Aluminum Oxides, Calcite, Carbonate, Iron Oxides, Silica   
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica   

Compound Content
Al, Aluminium Oxide, CaO, Carbon Dioxide, MgO, Silicon Dioxide   
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide   

Transformation
  
  

Metamorphism
Yes   
Yes   

Types of Metamorphism
Burial Metamorphism, Impact Metamorphism   
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, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion   
Chemical Erosion, Coastal Erosion, Glacier Erosion   

Properties

Physical Properties
  
  

Hardness
6   
6-7   

Grain Size
Fine Grained   
Fine Grained   

Fracture
Planar   
Irregular   

Streak
White, Greenish White or Grey   
White   

Porosity
Highly Porous   
Less Porous   

Luster
Earthy   
Dull   

Compressive Strength
51.20 N/mm2   
26
Not Available   

Cleavage
Perfect   
Imperfect   

Toughness
3   
1.7   

Specific Gravity
2.86   
2.5-4   

Transparency
Opaque   
Translucent to Opaque   

Density
0.25-0.3 g/cm3   
2.5-2.52 g/cm3   

Thermal Properties
  
  

Specific Heat Capacity
0.87 kJ/Kg K   
14
Not Available   

Resistance
Impact Resistant, Pressure Resistant   
Heat Resistant, Impact Resistant   

Reserves

Deposits in Eastern Continents
  
  

Asia
Afghanistan, Indonesia, Japan, Russia   
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam   

Africa
Ethiopia, Kenya, Tanzania   
Egypt, Ethiopia, Ghana, South Africa   

Europe
Greece, Hungary, Iceland, Italy, Turkey   
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
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA   
Canada, Cuba, Jamaica, USA   

South America
Argentina, Chile, Ecuador, Peru   
Bolivia, Brazil, Colombia, Ecuador, Paraguay   

Deposits in Oceania Continent
  
  

Australia
New Zealand, Western Australia   
New South Wales, New Zealand, Western Australia   

Summary >>
<< Reserves

All about Pumice and Porphyry Properties

Know all about Pumice and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Pumice and Porphyry belong to Igneous Rocks.Texture of Pumice is Vesicular whereas that of Porphyry is Porphyritic. Pumice appears Vesicular and Porphyry appears Dull. The luster of Pumice is earthy while that of Porphyry is dull. Pumice is available in beige, colourless, grey, light green, light grey, pink, white, yellow- grey colors whereas Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. The commercial uses of Pumice are as a traction material on snow-covered roads, as an abrasive in pencil erasers, fine abrasive used for polishing, manufacture of soap, solvents, dyes, plastics and fibres, used in aquariums and that of Porphyry are creating artwork, gemstone, jewelry.

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