Definition
Pantellerite is a peralkaline rhyolite. It has a higher iron and lower aluminium composition than comendite
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
History
Origin
Strait of sicily
Ethiopia
Discoverer
Unknown
Obsius
Etymology
From Pantelleria, a volcanic island in the Strait of Sicily
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Eutaxitic
Glassy
Color
Dark Greenish - Grey
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Layered and Foliated
Shiny
Architecture
Interior Uses
-
Decorative Aggregates, Interior Decoration
Exterior Uses
-
Garden Decoration
Other Architectural Uses
-
-
Industry
Construction Industry
-
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery
Other Uses
Commercial Uses
Creating Artwork
Creating Artwork, Mirror, Used in aquariums
Types
Pantelleritic Ignimbrite
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
High Fe content
Blocks negativity, Helps to protect against depression
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
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.
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
Composition
Mineral Content
Amphibole, Feldspar, Ilmenite
-
Compound Content
Al, Fe
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Physical Properties
Hardness
6-75-5.5
1
7
👆🏻
Grain Size
Fine Grained
-
Fracture
Sub-conchoidal
Conchoidal
Streak
-
White
Porosity
Less Porous
Very Less Porous
Luster
Earthy
Vitreous
Compressive Strength
210.00 N/mm20.15 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
-
Toughness
2
-
Specific Gravity
-99992.6-2.7
0
8.4
👆🏻
Transparency
Translucent to Opaque
Translucent
Density
-9999 g/cm32.6 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India
Afghanistan, Indonesia, Japan, Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria
Kenya
Europe
Germany, Iceland, Ireland, Italy, Spain, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
-
-
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Argentina, Bolivia, Brazil, Colombia, Ecuador
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Central Australia, Queensland, Western Australia
New Zealand