Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Pantellerite is a peralkaline rhyolite. It has a higher iron and lower aluminium composition than comendite
History
Origin
Italy
Strait of sicily
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From Pantelleria, a volcanic island in the Strait of Sicily
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Eutaxitic
Color
Blue, Bluish - Grey
Dark Greenish - Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Foliated
Layered and Foliated
Architecture
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
-
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
-
Other Architectural Uses
Curbing
-
Industry
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
-
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Sculpture
Other Uses
Commercial Uses
Cemetery Markers
Creating Artwork
Types
Rhyolite
Pantelleritic Ignimbrite
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
High Fe content
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
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.
Pantellerite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Composition
Mineral Content
Albite, Amphibole, Quartz
Amphibole, Feldspar, Ilmenite
Compound Content
Al, Fe, Potassium Oxide
Al, Fe
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
6-76-7
1
7
👆🏻
Grain Size
Medium Grained
Fine Grained
Fracture
Pervasive
Sub-conchoidal
Streak
Bluish Black
-
Porosity
Highly Porous
Less Porous
Luster
Dull
Earthy
Compressive Strength
92.40 N/mm2210.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Conchoidal
Toughness
2
2
Specific Gravity
2.38-9999
0
8.4
👆🏻
Transparency
Opaque
Translucent to Opaque
Density
-9999 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.79 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China
China, India
Africa
East Africa
Angola, Egypt, Madagascar, Namibia, Nigeria
Europe
Italy
Germany, Iceland, Ireland, Italy, Spain, United Kingdom
Others
-
-
Deposits in Western Continents
North America
-
Canada, USA
South America
-
Argentina, Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Queensland
Central Australia, Queensland, Western Australia