Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
  
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
  
History
  
  
Origin
USA
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
  
From the mineral feldspathoid which is the main content of rock
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Quench
  
Earthy
  
Color
Black, Brown, Colourless, Green, Grey, Pink, White
  
Black, Brown, Colourless, Green, Grey, Pink, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Dull and Soft
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
  
As Dimension Stone, Cement Manufacture, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Taken as a Supplement for Calcium or Magnesium
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone
  
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Types
Not Available
  
Not Available
  
Features
Host Rock for Lead
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
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.
  
Foidolites is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
  
Composition
  
  
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
  
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
  
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Weathering
No
  
No
  
Types of Weathering
Not Applicable
  
Not Applicable
  
Erosion
No
  
No
  
Types of Erosion
Not Applicable
  
Not Applicable
  
Physical Properties
  
  
Hardness
7
  
1.5
  
Grain Size
Very fine-grained
  
Medium to Fine Coarse Grained
  
Fracture
Uneven
  
Conchoidal
  
Streak
Light to dark brown
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Vitreous
  
Subvitreous to Dull
  
Compressive Strength
60.00 N/mm
2
  
25
Not Available
  
Cleavage
Irregular
  
Perfect
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
2.46-2.86
  
2.86
  
Transparency
Transparent to Translucent
  
Translucent
  
Density
2.7-2.9 g/cm3
  
Not Available
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant
  
Heat Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
South Korea
  
Russia
  
Africa
Western Africa
  
South Africa, Western Africa
  
Europe
Great Britain, Switzerland
  
Not Yet Found
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Not Yet Found
  
Canada, USA
  
South America
Not Yet Found
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
Central Australia, Western Australia
  
Central Australia, Western Australia
  
Pseudotachylite vs Foidolite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Pseudotachylite vs Foidolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pseudotachylite and Properties of Foidolite. Learn more about Pseudotachylite vs Foidolite in the next section. The interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Foidolite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Pseudotachylite and Foidolite, they have various applications in construction industry. The uses of Pseudotachylite in construction industry include As dimension stone, Cement manufacture, For road aggregate, Making natural cement and that of Foidolite include As dimension stone, Cement manufacture, For road aggregate.
More about Pseudotachylite and Foidolite
Here you can know more about Pseudotachylite and Foidolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pseudotachylite and Foidolite consists of mineral content and compound content. The mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides and mineral content of Foidolite includes Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Pseudotachylite vs Foidolite, the texture, color and appearance plays an important role in determining the type of rock. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas, Foidolite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Pseudotachylite is Dull and Soft and that of Foidolite is Dull. Properties of rock is another aspect for Pseudotachylite vs Foidolite. The hardness of Pseudotachylite is 7 and that of Foidolite is 1.5. The types of Pseudotachylite are Not Available whereas types of Foidolite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Pseudotachylite is light to dark brown while that of Foidolite is white. The specific heat capacity of Pseudotachylite is 0.92 kJ/Kg K and that of Foidolite is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Pseudotachylite is heat resistant whereas Foidolite is heat resistant, wear resistant.