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
  
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
  
History
  
  
Origin
France
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Latin varius, speckled, variegated
  
From the mineral feldspathoid which is the main content of rock
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Volcanic
  
Plutonic
  
Other Categories
Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
  
Earthy
  
Color
Black, Brown, Light to Dark Grey
  
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
No
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Dull and Soft
  
Dull
  
Architecture
  
  
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
Garden Decoration, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
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
  
Taken as a Supplement for Calcium or Magnesium
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Creating Artwork
  
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Types
Not Available
  
Not Available
  
Features
Has High structural resistance against erosion and climate, Very fine grained rock
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
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.
  
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
Olivine, Plagioclase, Pyroxene
  
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Weathering
Yes
  
No
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Not Applicable
  
Erosion
No
  
No
  
Types of Erosion
Not Applicable
  
Not Applicable
  
Physical Properties
  
  
Hardness
6
  
1.5
  
Grain Size
Not Applicable
  
Medium to Fine Coarse Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White to Grey
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Not Available
  
Subvitreous to Dull
  
Compressive Strength
37.50 N/mm
2
  
27
Not Available
  
Cleavage
Not Available
  
Perfect
  
Toughness
2.3
  
Not Available
  
Specific Gravity
2.8-3
  
2.86
  
Transparency
Opaque
  
Translucent
  
Density
2.9-3.1 g/cm3
  
Not Available
  
Thermal Properties
  
  
Specific Heat Capacity
0.84 kJ/Kg K
  
15
Not Available
  
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Russia
  
Africa
South Africa
  
South Africa, Western Africa
  
Europe
Iceland
  
Not Yet Found
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
Central Australia, Western Australia
  
All about Variolite and Foidolite Properties
Know all about Variolite and Foidolite properties here. All properties of rocks are important as they define the type of rock and its application. Variolite and Foidolite belong to Igneous Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Foidolite is Earthy. Variolite appears Dull and Soft and Foidolite appears Dull. The luster of Variolite is not available while that of Foidolite is subvitreous to dull. Variolite is available in black, brown, light to dark grey colors whereas Foidolite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Variolite are cemetery markers, creating artwork and that of Foidolite are cemetery markers, commemorative tablets, creating artwork.