Definition
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Discoverer
Unknown
Unknown
Etymology
From the mineral feldspathoid which is the main content of rock
From a Latin word tophous then in Italian tufo and finally tuff
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy
Clastic, Pyroclastic
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Brown, Grey, Yellow
Durability
Durable
Durable
Appearance
Dull
Dull, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Building houses or walls, Construction Aggregate
Medical Industry
Taken as a Supplement for Calcium or Magnesium
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork
Types
Not Available
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Features
Host Rock for Lead
Always found as volcanic pipes over deep continental crust
Archaeological Significance
Famous Monuments
Data Not Available
Easter Island in the Polynesian Triangle, Pacific Ocean
Famous Sculptures
Data Not Available
Data Not Available
Formation
Foidolites 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.
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.
Mineral Content
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Calcite, Chlorite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Hydrogen Sulfide, Sulfur Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Uneven
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Vitreous to Dull
Compressive Strength
Not Available
Cleavage
Perfect
Not Available
Toughness
Not Available
Not Available
Specific Gravity
2.86
2.73
Transparency
Translucent
Opaque
Density
Not Available
1-1.8 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
Africa
South Africa, Western Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Europe
Not Yet Found
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
Not Yet Found
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Panama, USA
South America
Not Yet Found
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Central Australia, Western Australia