Variolite and Anorthosite
Definition
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
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
History
Origin
France
Unknown
Discoverer
Unknown
Unknown
Etymology
From Latin varius, speckled, variegated
From French anorthose plagioclase + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Plutonic
Other Categories
Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Foliated, Glassy
Color
Black, Brown, Light to Dark Grey
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
No
Stain Resistant
No
No
Wind Resistant
No
Yes
Acid Resistant
Yes
No
Appearance
Dull and Soft
Layered, Banded, Veined and Shiny
Uses
Architecture
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture, Small Figurines
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Curling
Types
Types
Not Available
Proterozoic Anorthosite and Archean Anorthosite
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Used
Fossils
Absent
Absent
Formation
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.
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
Composition
Mineral Content
Olivine, Plagioclase, Pyroxene
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
Transformation
Metamorphism
Yes
Yes
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Erosion
No
Yes
Types of Erosion
Not Applicable
Chemical Erosion, Wind Erosion
Properties
Physical Properties
Hardness
6
5-6
Grain Size
Not Applicable
Coarse Grained
Fracture
Conchoidal
Irregular
Streak
White to Grey
White
Porosity
Less Porous
Less Porous
Luster
Not Available
Pearly to Subvitreous
Compressive Strength
37.50 N/mm2
27
Not Available
Cleavage
Not Available
Irregular
Toughness
2.3
Not Available
Specific Gravity
2.8-3
2.62-2.82
Transparency
Opaque
Translucent
Density
2.9-3.1 g/cm3
2.7-4 g/cm3
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K
15
0.84 kJ/Kg K
15
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Reserves
Deposits in Eastern Continents
Asia
India, Russia
Not Yet Found
Africa
South Africa
Not Yet Found
Europe
Iceland
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Brazil
Bolivia, Colombia
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, South Australia, Western Australia
All about Variolite and Anorthosite Properties
Know all about Variolite and Anorthosite properties here. All properties of rocks are important as they define the type of rock and its application. Variolite and Anorthosite belong to Igneous Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Anorthosite is Foliated, Glassy. Variolite appears Dull and Soft and Anorthosite appears Layered, Banded, Veined and Shiny. The luster of Variolite is not available while that of Anorthosite is pearly to subvitreous. Variolite is available in black, brown, light to dark grey colors whereas Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors. The commercial uses of Variolite are cemetery markers, creating artwork and that of Anorthosite are creating artwork, curling.
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