Definition
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
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Unknown
Unknown
Etymology
From Latin varius, speckled, variegated
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Quench
Color
Black, Brown, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone
Types
Not Available
Not Available
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Not Yet Used
Formation
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
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.
Mineral Content
Olivine, Plagioclase, Pyroxene
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Not Applicable
Not Applicable
Grain Size
Not Applicable
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
White to Grey
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Not Available
Vitreous
Cleavage
Not Available
Irregular
Toughness
2.3
Not Available
Specific Gravity
2.8-3
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
2.9-3.1 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Russia
South Korea
Africa
South Africa
Western Africa
Europe
Iceland
Great Britain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Not Yet Found
South America
Brazil
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, Western Australia
All about Variolite and Pseudotachylite Properties
Know all about Variolite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Variolite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Pseudotachylite is Quench. Variolite appears Dull and Soft and Pseudotachylite appears Dull and Soft. The luster of Variolite is not available while that of Pseudotachylite is vitreous. Variolite is available in black, brown, light to dark grey colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Variolite are cemetery markers, creating artwork and that of Pseudotachylite are creating artwork, gemstone.