1 Definition
1.1 Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From a Latin word tophous then in Italian tufo and finally tuff
From Cornish gossen from gos, blood from Old Cornish guit
1.4 Class
Igneous Rocks
Metamorphic Rocks
1.4.1 Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Clastic, Pyroclastic
Rough, Sandy
2.2 Color
Brown, Grey, Yellow
Brown, Brown- Black, Gold, Green, Rust
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
Dull, Vesicular and Foilated
Dull and Banded
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
3.4 Other Uses
3.4.1 Commercial Uses
Creating Artwork
Cemetery Markers, Commemorative Tablets, Gemstone
4 Types
4.1 Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Translocated gossan and Leakage gossan
4.2 Features
Always found as volcanic pipes over deep continental crust
Clasts are smooth to touch, Easily splits into thin plates
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean
Not Applicable
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Not Applicable
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
5.2 Composition
5.2.1 Mineral Content
Calcite, Chlorite
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
5.2.2 Compound Content
Hydrogen Sulfide, Sulfur Dioxide
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Fine Grained
Fine to Medium Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Highly Porous
Highly Porous
6.1.6 Luster
Vitreous to Dull
Metallic
6.1.7 Compressive Strength
6.1.8 Cleavage
Not Available
Not Available
6.1.9 Toughness
Not Available
Not Available
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
1-1.8 g/cm3Not Available
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.20 kJ/Kg K0.24 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
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 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, India, Indonesia, Russia, Singapore, South Korea
7.1.2 Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
7.1.3 Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Albania, France, Germany, Great Britain, United Kingdom
7.1.4 Others
Antarctica, Hawaii Islands
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
Canada, Costa Rica, Panama, USA
Canada, USA
7.2.2 South America
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Brazil, Colombia, Ecuador
7.3 Deposits in Oceania Continent
7.3.1 Australia
Central Australia, Western Australia
New South Wales, South Australia, Western Australia