1 Definition
1.1 Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
1.2 History
1.2.1 Origin
Romania and Moldova, Europe
Italy
1.2.2 Discoverer
1.3 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 a Latin word tophous then in Italian tufo and finally tuff
1.4 Class
Igneous Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Aphanitic to Porphyritic
Clastic, Pyroclastic
2.2 Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Brown, Grey, Yellow
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
Vesicular
Dull, Vesicular and Foilated
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Building houses or walls, Construction Aggregate
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
3.4 Other Uses
3.4.1 Commercial Uses
Commemorative Tablets, Creating Artwork
Creating Artwork
4 Types
4.1 Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
4.2 Features
Host Rock for Lead, Is one of the oldest rock
Always found as volcanic pipes over deep continental crust
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Not Applicable
Easter Island in the Polynesian Triangle, Pacific Ocean
4.3.3 Sculpture
4.3.4 Famous Sculptures
Not Applicable
Data Not Available
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
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.
5.2 Composition
5.2.1 Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Calcite, Chlorite
5.2.2 Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Hydrogen Sulfide, Sulfur Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Medium to Fine Coarse Grained
Fine Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Less Porous
Highly Porous
6.1.6 Luster
Subvitreous to Dull
Vitreous to Dull
6.1.7 Compressive Strength
6.1.8 Cleavage
6.1.9 Toughness
Not Available
Not Available
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
2.77-2.771 g/cm31-1.8 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K0.20 kJ/Kg K
0.14
3.2
6.2.2 Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Not Yet Found
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
7.1.2 Africa
Not Yet Found
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
7.1.3 Europe
France, Greece, Romania, Scotland, Spain
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
7.1.4 Others
Not Yet Found
Antarctica, Hawaii Islands
7.2 Deposits in Western Continents
7.2.1 North America
USA
Canada, Costa Rica, Panama, USA
7.2.2 South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, South Australia, Western Australia
Central Australia, Western Australia