Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Jasperoid is a rare, peculiar type of metasomatic alteration of rocks
Discoverer
Unknown
Unknown
Etymology
From a Latin word tophous then in Italian tufo and finally tuff
From silica, the main mineral content of Jasperoid
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic, Pyroclastic
Earthy
Color
Brown, Grey, Yellow
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Vesicular and Foilated
Glassy or Pearly
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock
Medical Industry
Not Yet Used
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Creating Artwork
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Not Available
Features
Always found as volcanic pipes over deep continental crust
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits
Archaeological Significance
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
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.
Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.
Mineral Content
Calcite, Chlorite
Clay Minerals, Pyrite, Quartz, Sulfides
Compound Content
Hydrogen Sulfide, Sulfur Dioxide
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
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
Not Applicable
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Not Applicable
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Vitreous to Dull
Vitreous and Pearly
Cleavage
Not Available
Perfect
Toughness
Not Available
1
Specific Gravity
2.73
2.8-3
Transparency
Opaque
Transparent to Translucent
Density
1-1.8 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear 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
Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Morocco, Namibia
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Austria, Italy, Romania, Spain, Switzerland
Others
Antarctica, Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Mexico, USA
South America
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Brazil, Colombia
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, Queensland, Yorke Peninsula