Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Conglomerate is a sedimentary rock which forms from rounded gravel and boulder sized clasts which are cemented together in a matrix
Discoverer
Unknown
Unknown
Etymology
From a Latin word tophous then in Italian tufo and finally tuff
From Latin conglomeratus, to roll together, i.e. from com together + glomerare to gather into a ball, from glomus (genitive glomeris) a ball
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Clastic, Pyroclastic
Clastic
Color
Brown, Grey, Yellow
Beige, Black, Brown, Buff, Light to Dark Grey, Orange, Rust, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Vesicular and Foilated
Shiny and Rounded
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork
Cemetery Markers, In aquifers, Tombstones
Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Orthoconglomerate and Paraconglomerate
Features
Always found as volcanic pipes over deep continental crust
Clasts are smooth to touch, Is one of the oldest rock, Matrix variable
Archaeological Significance
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean
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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.
Conglomerate forms where sediments consisting mainly of pebble and cobble-size clasts at least two millimeters in diameter starts accumulating.
Mineral Content
Calcite, Chlorite
Clay, Sand, Silica, Silt
Compound Content
Hydrogen Sulfide, Sulfur Dioxide
NaCl, CaO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
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Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Fine Grained
Coarse Grained
Porosity
Highly Porous
Highly Porous
Luster
Vitreous to Dull
Dull
Specific Gravity
2.73
2.86-2.88
Transparency
Opaque
Opaque
Density
1-1.8 g/cm3
1.7-2.3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
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, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Namibia, Nigeria, South Africa
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Antarctica, Hawaii Islands
Greenland
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada, USA
South America
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand