Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
  
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
  
History
  
  
Origin
USA
  
North America
  
Discoverer
Unknown
  
Unknown
  
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
  
From Andes mountains, where it is found in abundance
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Quench
  
Aphanitic to Porphyritic
  
Color
Black, Brown, Colourless, Green, Grey, Pink, White
  
Bluish - Grey, Grey, Pink, Yellow
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull and Soft
  
Dull and Soft
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
  
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
  
Office Buildings, Roof Tiles
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
  
Cobblestones, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone
  
Commemorative Tablets, Creating Artwork
  
Types
Not Available
  
Icelandite
  
Features
Host Rock for Lead
  
Generally rough to touch, High silica content, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Middle of the Earth in Ecuador
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
  
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
  
Composition
  
  
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
  
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
  
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
  
Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
7
  
7
  
Grain Size
Very fine-grained
  
Very fine-grained
  
Fracture
Uneven
  
Uneven
  
Streak
Light to dark brown
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Vitreous
  
Vitreous
  
Compressive Strength
60.00 N/mm2
  
25
225.00 N/mm2
  
7
Cleavage
Irregular
  
Not Available
  
Toughness
Not Available
  
1.1
  
Specific Gravity
2.46-2.86
  
2.5-2.8
  
Transparency
Transparent to Translucent
  
Opaque
  
Density
2.7-2.9 g/cm3
  
2.11-2.36 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
2.39 kJ/Kg K
  
2
Resistance
Heat Resistant
  
Heat Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
South Korea
  
India, Indonesia, Japan, Nepal, South Korea
  
Africa
Western Africa
  
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
  
Europe
Great Britain, Switzerland
  
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Not Yet Found
  
Mexico, USA
  
South America
Not Yet Found
  
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Central Australia, Western Australia
  
New South Wales, New Zealand, Western Australia