Pumice and Porphyry
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
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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