Definition
Diorite is a grey to dark-grey intermediate intrusive igneous rock composed principally of plagioclase feldspar,biotite, hornblende, and pyroxene
Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture
Discoverer
Unknown
Warren Hamilton
Etymology
From early 19th century coined in French, formed irregularly from Greek diorizein distinguish
From Tonale Pass, northern Italy, + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Phaneritic
Phaneritic
Color
Black, Brown, Light to Dark Grey, White
Black, Brown, Light to Dark Grey, White
Durability
Durable
Durable
Appearance
Shiny
Banded and Foilated
Interior Uses
Decorative Aggregates, 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, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture
Commercial Uses
Creating Artwork, Curling
Cemetery Markers, Creating Artwork
Types
Plagioclase Diorite and Quartz Diorite
Dacite
Features
Typically speckled black and white.
Is one of the oldest rock, Typically speckled black and white.
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.
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes tonalite with quartz as major mineral.
Mineral Content
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Muscovite or Illite, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
Silicon Dioxide
NaCl, CaO, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Wind Erosion
Grain Size
Medium to Coarse Grained
Medium to Fine Coarse Grained
Streak
Bluish Black
Bluish Black
Porosity
Very Less Porous
Very Less Porous
Luster
Shiny
Subvitreous to Dull
Specific Gravity
2.8-3
2.86-3
Transparency
Opaque
Opaque
Density
2.8-3 g/cm3
2.73 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Europe
Finland, Germany, Italy, Romania, Sweden, Turkey, United Kingdom
Finland, Germany, Italy, Romania, Sweden, Turkey
Deposits in Western Continents
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand, South Australia, Western Australia