Definition
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Basaltic Trachyandesite is an extrusive igneous rock which is a type of Basalt rock and is formed by the rapid cooling of basaltic lava exposed at or very near the Earth's surface
Discoverer
Theodor von Gümbel
Unknown
Etymology
From Andes mountains, where it is found in abundance
From its mineral and compound content and its relation with Basalt and Andesite rock
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Bluish - Grey, Grey, Pink, Yellow
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
Office Buildings, Roof Tiles
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
Cobblestones, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Commemorative Tablets, Creating Artwork
An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork
Types
Icelandite
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Features
Generally rough to touch, High silica content, Is one of the oldest rock
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Famous Monuments
Middle of the Earth in Ecuador
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Formation
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Basaltic Trachandesite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Olivine, Plagioclase, Pyroxene
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
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
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Grain Size
Very fine-grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
White
White to Grey
Porosity
Less Porous
Less Porous
Specific Gravity
2.5-2.8
2.8-3
Transparency
Opaque
Opaque
Density
2.11-2.36 g/cm3
2.9-3.1 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Indonesia, Japan, Nepal, South Korea
India, Russia
Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
South Africa
Europe
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Iceland
Deposits in Western Continents
North America
Mexico, USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
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