Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
Discoverer
Unknown
Patrick Marshall
Etymology
From French anorthose plagioclase + -ite1
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
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
Aphanitic
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Beige, Black, Brown, Grey, Pink, White
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Dull, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building 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
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Proterozoic Anorthosite and Archean Anorthosite
Pyroclastic rock
Features
Generally rough to touch, Is one of the oldest rock
Always found as volcanic pipes over deep continental crust
Archaeological Significance
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.
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Ca, NaCl
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Wind Erosion
Chemical Erosion, Coastal 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, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, 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, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
Central Australia, Western Australia