Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From Latin varius, speckled, variegated
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Quench
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Brown, Green, Grey, Pink, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Gemstone
Cemetery Markers, Creating Artwork
Types
Cataclastic rock
Metamorphic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
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.
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Olivine, Plagioclase, Pyroxene
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
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
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Grain Size
Very fine-grained
-
Fracture
Uneven
Conchoidal
Streak
Light to dark brown
White to Grey
Porosity
Less Porous
Less Porous
Specific Gravity
2.46-2.86
2.8-3
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
2.9-3.1 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
South Korea
India, Russia
Africa
Western Africa
South Africa
Europe
Great Britain, Switzerland
Iceland
Deposits in Western Continents
North America
-
Canada, USA
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-
Pseudotachylite vs Variolite 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 Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pseudotachylite and Properties of Variolite. Learn more about Pseudotachylite vs Variolite in the next section. The interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Pseudotachylite and Variolite, 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 Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Pseudotachylite and Variolite
Here you can know more about Pseudotachylite and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pseudotachylite and Variolite consists of mineral content and compound content. The mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides and mineral content of Variolite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Pseudotachylite vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Pseudotachylite is available in black, brown, green, grey, pink, white colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Pseudotachylite is Dull and Soft and that of Variolite is Dull and Soft. Properties of rock is another aspect for Pseudotachylite vs Variolite. The hardness of Pseudotachylite is 7 and that of Variolite is 6. The types of Pseudotachylite are Cataclastic rock whereas types of Variolite are Metamorphic rock. 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 Variolite is white to grey. The specific heat capacity of Pseudotachylite is 0.92 kJ/Kg K and that of Variolite is 0.84 kJ/Kg K. 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 Variolite is heat resistant, pressure resistant, wear resistant.