Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Discoverer
Unknown
Unknown
Etymology
From a Latin word tophous then in Italian tufo and finally tuff
From French anorthose plagioclase + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Clastic, Pyroclastic
Foliated, Glassy
Color
Brown, Grey, Yellow
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull, Vesicular and Foilated
Layered, Banded, Veined and Shiny
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, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork
Creating Artwork, Curling
Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Proterozoic Anorthosite and Archean Anorthosite
Features
Always found as volcanic pipes over deep continental crust
Generally rough to touch, Is one of the oldest rock
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.
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
Mineral Content
Calcite, Chlorite
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Compound Content
Hydrogen Sulfide, Sulfur Dioxide
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Wind Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Uneven
Irregular
Porosity
Highly Porous
Less Porous
Luster
Vitreous to Dull
Pearly to Subvitreous
Specific Gravity
2.73
2.62-2.82
Transparency
Opaque
Translucent
Density
1-1.8 g/cm3
2.7-4 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch 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
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Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
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Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Others
Antarctica, Hawaii Islands
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Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada
South America
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Bolivia, Colombia
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Central Australia, South Australia, Western Australia