Definition
Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
History
Origin
Spain
Italy
Discoverer
Unknown
Unknown
Etymology
From Old French pomis, from a Latin dialect variant of pumex
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Vesicular
Porphyritic
Color
Beige, Grey, Light Green, Light Grey, Pink, White, Yellow- grey
Blue, Bluish - Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Foliated
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
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
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
As an abrasive in skin exfoliating products, In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
-
Antiquity Uses
Artifacts
Artifacts
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
Cemetery Markers
Types
Scoria
Rhyolite
Features
Host Rock for Lead
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
Comendite is a type of Igneous rock which is formed due to cooling and solidification of lava or magma. It may form with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Composition
Mineral Content
Aluminum Oxides, Calcite, Carbonate, Iron Oxides, Silica
Albite, Amphibole, Quartz
Compound Content
Al, Aluminium Oxide, CaO, Carbon Dioxide, MgO, Silicon Dioxide
Al, Fe, Potassium Oxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Physical Properties
Hardness
66-7
1
7
👆🏻
Grain Size
Fine Grained
Medium Grained
Fracture
Planar
Pervasive
Streak
White, Greenish White or Grey
Bluish Black
Porosity
Highly Porous
Highly Porous
Luster
Earthy
Dull
Compressive Strength
51.20 N/mm292.40 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
3
2
Specific Gravity
2.862.38
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
0.25-0.3 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.87 kJ/Kg K0.79 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
China
Africa
Ethiopia, Kenya, Tanzania
East Africa
Europe
Greece, Hungary, Iceland, Italy, Turkey
Italy
Others
-
-
Deposits in Western Continents
North America
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
-
South America
Argentina, Chile, Ecuador, Peru
-
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Queensland