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
Discoverer
Unknown
Theodor von Gümbel
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
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Quench
Aphanitic to Porphyritic
Color
Black, Brown, Green, Grey, Pink, White
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
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
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Cobblestones, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone
Commemorative Tablets, Creating Artwork
Types
Cataclastic rock
Icelandite
Features
Host Rock for Lead
Generally rough to touch, High silica content, Is one of the oldest rock
Archaeological Significance
Famous Monuments
-
Middle of the Earth in Ecuador
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.
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Very fine-grained
Very fine-grained
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
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
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
Deposits in Western Continents
North America
-
Mexico, USA
South America
-
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Western Australia