Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Pantellerite is a peralkaline rhyolite. It has a higher iron and lower aluminium composition than comendite
History
Origin
Romania and Moldova, Europe
Strait of sicily
Discoverer
Unknown
Unknown
Etymology
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
From Pantelleria, a volcanic island in the Strait of Sicily
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Eutaxitic
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Dark Greenish - Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Layered and Foliated
Architecture
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
-
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
-
Other Architectural Uses
Curbing
-
Industry
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
-
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Sculpture
Other Uses
Commercial Uses
Commemorative Tablets, Creating Artwork
Creating Artwork
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Pantelleritic Ignimbrite
Features
Host Rock for Lead, Is one of the oldest rock
High Fe content
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
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
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Amphibole, Feldspar, Ilmenite
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Al, Fe
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
2-2.256-7
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Sub-conchoidal
Streak
White
-
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Earthy
Compressive Strength
70.00 N/mm2210.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
Conchoidal
Toughness
-
2
Specific Gravity
2.86-2.87-9999
0
8.4
👆🏻
Transparency
Translucent
Translucent to Opaque
Density
2.77-2.771 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
-
China, India
Africa
-
Angola, Egypt, Madagascar, Namibia, Nigeria
Europe
France, Greece, Romania, Scotland, Spain
Germany, Iceland, Ireland, Italy, Spain, United Kingdom
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Argentina, Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, Queensland, Western Australia