Definition
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Syenite is a coarse-grained igneous rock which is composed mainly of alkali feldspar and various ferromagnesian minerals
History
Origin
North America
-
Discoverer
Theodor von Gümbel
Unknown
Etymology
From Andes mountains, where it is found in abundance
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
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy
Color
Bluish - Grey, Grey, Pink, Yellow
Brown, Buff, Cream, Green, Grey, Pink, White
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull and Soft
Banded and Foilated
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Flooring, Homes, Hotels, Interior Decoration
Exterior Uses
Office Buildings, Roof Tiles
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
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
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork
Types
Icelandite
Shonkinite
Features
Generally rough to touch, High silica content, Is one of the oldest rock
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Archaeological Significance
Monuments
-
-
Famous Monuments
Middle of the Earth in Ecuador
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Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Composition
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, 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
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
75.5-6
1
7
👆🏻
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Fracture
Uneven
-
Streak
White
White
Porosity
Less Porous
Less Porous
Luster
Vitreous
Subvitreous to Dull
Compressive Strength
225.00 N/mm2150.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
1.1
-
Specific Gravity
2.5-2.82.6-2.7
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.11-2.36 g/cm32.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
2.39 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Indonesia, Japan, Nepal, South Korea
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Bulgaria, England, Germany, Norway, Romania, Switzerland
Others
-
-
Deposits in Western Continents
North America
Mexico, USA
USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Chile
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New Zealand, Queensland, South Australia, Western Australia