Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
Discoverer
Unknown
Unknown
Etymology
From French anorthose plagioclase + -ite1
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
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
Earthy
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black to Grey, Dark Greenish - Grey
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Skeletal
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts
Commercial Uses
Creating Artwork, Curling
Cemetery Markers, Creating Artwork
Types
Proterozoic Anorthosite and Archean Anorthosite
Not Available
Features
Generally rough to touch, Is one of the oldest rock
Available in Lots of Colors and Patterns
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Used
Not Yet Used
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.
Rhyodacite 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.
Mineral Content
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Ca, Fe, Potassium Oxide, NA, Potassium, Silicon 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
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Less Porous
Luster
Pearly to Subvitreous
Greasy to Dull
Compressive Strength
Not Available
Cleavage
Irregular
Not Available
Toughness
Not Available
2.1
Specific Gravity
2.62-2.82
2.34-2.40
Transparency
Translucent
Opaque
Density
2.7-4 g/cm3
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Not Yet Found
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada
Canada, USA
South America
Bolivia, Colombia
Not Yet Found
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
Not Yet Found