Definition
Diorite is a grey to dark-grey intermediate intrusive igneous rock composed principally of plagioclase feldspar,biotite, hornblende, and pyroxene
Syenite is a coarse-grained igneous rock which is composed mainly of alkali feldspar and various ferromagnesian minerals
Discoverer
Unknown
Unknown
Etymology
From early 19th century coined in French, formed irregularly from Greek diorizein distinguish
From French syénite, from Latin Syenites (lapis ) (stone) of Syene
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, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Phaneritic
Earthy
Color
Black, Brown, Light to Dark Grey, White
Brown, Buff, Cream, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Shiny
Banded and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Flooring, Homes, Hotels, 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, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Curling
Cemetery Markers, Creating Artwork
Types
Plagioclase Diorite and Quartz Diorite
Shonkinite
Features
Typically speckled black and white.
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
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.
Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Mineral Content
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Muscovite or Illite, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium 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
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Coarse Grained
Medium to Fine Coarse Grained
Streak
Bluish Black
White
Porosity
Very Less Porous
Less Porous
Luster
Shiny
Subvitreous to Dull
Specific Gravity
2.8-3
2.6-2.7
Transparency
Opaque
Opaque
Density
2.8-3 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Egypt
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Finland, Germany, Italy, Romania, Sweden, Turkey, United Kingdom
Bulgaria, England, Germany, Norway, Romania, Switzerland
Deposits in Western Continents
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Brazil, Chile
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand, Queensland, South Australia, Western Australia
Diorite vs Syenite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Diorite vs Syenite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Diorite and Properties of Syenite. Learn more about Diorite vs Syenite in the next section. The interior uses of Diorite include Decorative aggregates and Interior decoration whereas the interior uses of Syenite include Flooring, Homes, Hotels and Interior decoration. Due to some exceptional properties of Diorite and Syenite, they have various applications in construction industry. The uses of Diorite in construction industry include As dimension stone, Cement manufacture, Cobblestones, Construction aggregate, For road aggregate and that of Syenite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Landscaping, Making natural cement, Manufacture of magnesium and dolomite refractories.
More about Diorite and Syenite
Here you can know more about Diorite and Syenite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Diorite and Syenite consists of mineral content and compound content. The mineral content of Diorite includes Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Muscovite or Illite, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon and mineral content of Syenite includes Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz. You can also check out the list of all Igneous Rocks. When we have to compare Diorite vs Syenite, the texture, color and appearance plays an important role in determining the type of rock. Diorite is available in black, brown, light to dark grey, white colors whereas, Syenite is available in brown, buff, cream, green, grey, pink, white colors. Appearance of Diorite is Shiny and that of Syenite is Banded and Foilated. Properties of rock is another aspect for Diorite vs Syenite. The hardness of Diorite is 6-7 and that of Syenite is 5.5-6. The types of Diorite are Plagioclase Diorite and Quartz Diorite whereas types of Syenite are Shonkinite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Diorite is bluish black while that of Syenite is white. The specific heat capacity of Diorite is 0.84 kJ/Kg K and that of Syenite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Diorite is heat resistant, pressure resistant, wear resistant whereas Syenite is heat resistant, impact resistant, wear resistant.