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