Definition
Syenite is a coarse-grained igneous rock which is composed mainly of alkali feldspar and various ferromagnesian minerals
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
History
Origin
-
Germany
Discoverer
Unknown
Christian Leopold von Buch
Etymology
From French syénite, from Latin Syenites (lapis ) (stone) of Syene
From Greek di + base
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy
Aphanitic, Granular
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Dark Grey to Black
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Banded and Foilated
Vesicular
Architecture
Interior Uses
Flooring, Homes, Hotels, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Shonkinite
Dolerite
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Smooth to touch
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Stonehenge in English county of Wiltshire
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
Composition
Mineral Content
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Physical Properties
Hardness
5.5-67
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine to Medium Grained
Fracture
-
Conchoidal
Streak
White
Black
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
-
Compressive Strength
150.00 N/mm2225.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
-
1.6
Specific Gravity
2.6-2.72.86-2.87
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm32.7-3.3 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
India
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
South Africa, Tanzania
Europe
Bulgaria, England, Germany, Norway, Romania, Switzerland
Germany, Greece, Italy, Scotland, Turkey
Others
-
Antarctica, Greenland
Deposits in Western Continents
North America
USA
Canada, USA
South America
Brazil, Chile
Argentina, Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Western Australia
Central Australia, New Zealand, Queensland, Western Australia