Definition
Diorite is a grey to dark-grey intermediate intrusive igneous rock composed principally of plagioclase feldspar,biotite, hornblende, and pyroxene
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Discoverer
Unknown
Unknown
Etymology
From early 19th century coined in French, formed irregularly from Greek diorizein distinguish
From French anorthose plagioclase + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Phaneritic
Foliated, Glassy
Color
Black, Brown, Light to Dark Grey, White
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Durability
Durable
Durable
Appearance
Shiny
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Curling
Creating Artwork, Curling
Types
Plagioclase Diorite and Quartz Diorite
Proterozoic Anorthosite and Archean Anorthosite
Features
Typically speckled black and white.
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Formation
Diorite is a coarse-grained intrusive igneous rock which contains large interlocking and randomly oriented crystals and forms when molten lava does not reach the Earth’s surface and cools down in the Earth’s crust.
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
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Muscovite or Illite, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Compound Content
Silicon Dioxide
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact 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, Water Erosion
Chemical Erosion, Wind Erosion
Grain Size
Medium to Coarse Grained
Coarse Grained
Streak
Bluish Black
White
Porosity
Very Less Porous
Less Porous
Luster
Shiny
Pearly to Subvitreous
Specific Gravity
2.8-3
2.62-2.82
Transparency
Opaque
Translucent
Density
2.8-3 g/cm3
2.7-4 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Europe
Finland, Germany, Italy, Romania, Sweden, Turkey, United Kingdom
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Deposits in Western Continents
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Bolivia, Colombia
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Central Australia, South Australia, Western Australia