Tuff and Comendite
Definition
Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
History
Origin
Italy
Italy
Discoverer
Unknown
Unknown
Etymology
From a Latin word tophous then in Italian tufo and finally tuff
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
Texture
Clastic, Pyroclastic
Porphyritic
Color
Brown, Grey, Yellow
Blue, Bluish - Grey
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
No
Yes
Wind Resistant
No
Yes
Acid Resistant
No
Yes
Appearance
Dull, Vesicular and Foilated
Foliated
Uses
Architecture
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Building houses or walls, Construction Aggregate
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Other Uses
Commercial Uses
Creating Artwork
Cemetery Markers
Types
Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Rhyolite
Features
Always found as volcanic pipes over deep continental crust
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Not Yet Used
Fossils
Absent
Absent
Formation
Formation
Tuff is formed when large masses of ash and sand which are mixed with hot gases are ejected by a volcano and avalanche rapidly down its slopes.
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
Calcite, Chlorite
Albite, Amphibole, Quartz
Compound Content
Hydrogen Sulfide, Sulfur Dioxide
Al, Fe, Potassium Oxide
Transformation
Metamorphism
Yes
Yes
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Properties
Physical Properties
Hardness
4-6
6-7
Grain Size
Fine Grained
Medium Grained
Fracture
Uneven
Pervasive
Streak
White
Bluish Black
Porosity
Highly Porous
Highly Porous
Luster
Vitreous to Dull
Dull
Compressive Strength
243.80 N/mm2
5
92.40 N/mm2
21
Cleavage
Not Available
Not Available
Toughness
Not Available
2
Specific Gravity
2.73
2.38
Transparency
Opaque
Opaque
Density
1-1.8 g/cm3
Not Available
Thermal Properties
Specific Heat Capacity
0.20 kJ/Kg K
25
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Reserves
Deposits in Eastern Continents
Asia
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
China
Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
East Africa
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Italy
Others
Antarctica, Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Not Yet Found
South America
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Not Yet Found
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Queensland
All about Tuff and Comendite Properties
Know all about Tuff and Comendite properties here. All properties of rocks are important as they define the type of rock and its application. Tuff and Comendite belong to Igneous Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Comendite is Porphyritic. Tuff appears Dull, Vesicular and Foilated and Comendite appears Foliated. The luster of Tuff is vitreous to dull while that of Comendite is dull. Tuff is available in brown, grey, yellow colors whereas Comendite is available in blue, bluish - grey colors. The commercial uses of Tuff are creating artwork and that of Comendite are cemetery markers.
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