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Foidolite and Variolite


Variolite and Foidolite


Definition

Definition
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%   
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   

History
  
  

Origin
Unknown   
France   

Discoverer
Unknown   
Unknown   

Etymology
From the mineral feldspathoid which is the main content of rock   
From Latin varius, speckled, variegated   

Class
Igneous Rocks   
Igneous Rocks   

Sub-Class
Durable Rock, Soft Rock   
Durable Rock, Hard Rock   

Family
  
  

Group
Plutonic   
Volcanic   

Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock   
Opaque Rock   

Texture

Texture
Earthy   
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular   

Color
Black, Brown, Colourless, Green, Grey, Pink, White   
Black, Brown, Light to Dark Grey   

Maintenance
Less   
Less   

Durability
Durable   
Durable   

Water Resistant
No   
Yes   

Scratch Resistant
No   
Yes   

Stain Resistant
No   
No   

Wind Resistant
No   
No   

Acid Resistant
No   
Yes   

Appearance
Dull   
Dull and Soft   

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Interior Decoration   
Floor Tiles, Flooring, Homes, Hotels, Kitchens   

Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone   
Garden Decoration, Office Buildings   

Other Architectural Uses
Curbing   
Curbing   

Industry
  
  

Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate   
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone   

Medical Industry
Taken as a Supplement for Calcium or Magnesium   
Not Yet Used   

Antiquity Uses
Artifacts, Monuments, Sculpture   
Artifacts, Monuments, Sculpture   

Other Uses
  
  

Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork   
Cemetery Markers, Creating Artwork   

Types

Types
Not Available   
Not Available   

Features
Host Rock for Lead   
Has High structural resistance against erosion and climate, Very fine grained rock   

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

Formation
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.   
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.   

Composition
  
  

Mineral Content
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene   
Olivine, Plagioclase, Pyroxene   

Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO   
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide   

Transformation
  
  

Metamorphism
Yes   
Yes   

Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism   
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism   

Weathering
No   
Yes   

Types of Weathering
Not Applicable   
Biological Weathering, Chemical Weathering, Mechanical Weathering   

Erosion
No   
No   

Types of Erosion
Not Applicable   
Not Applicable   

Properties

Physical Properties
  
  

Hardness
1.5   
6   

Grain Size
Medium to Fine Coarse Grained   
Not Applicable   

Fracture
Conchoidal   
Conchoidal   

Streak
White   
White to Grey   

Porosity
Very Less Porous   
Less Porous   

Luster
Subvitreous to Dull   
Not Available   

Compressive Strength
Not Available   
37.50 N/mm2   
27

Cleavage
Perfect   
Not Available   

Toughness
Not Available   
2.3   

Specific Gravity
2.86   
2.8-3   

Transparency
Translucent   
Opaque   

Density
Not Available   
2.9-3.1 g/cm3   

Thermal Properties
  
  

Specific Heat Capacity
Not Available   
0.84 kJ/Kg K   
15

Resistance
Heat Resistant, Wear Resistant   
Heat Resistant, Pressure Resistant, Wear Resistant   

Reserves

Deposits in Eastern Continents
  
  

Asia
Russia   
India, Russia   

Africa
South Africa, Western Africa   
South Africa   

Europe
Not Yet Found   
Iceland   

Others
Not Yet Found   
Not Yet Found   

Deposits in Western Continents
  
  

North America
Canada, USA   
Canada, USA   

South America
Not Yet Found   
Brazil   

Deposits in Oceania Continent
  
  

Australia
Central Australia, Western Australia   
Not Yet Found   

Summary >>
<< Reserves

All about Foidolite and Variolite Properties

Know all about Foidolite and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Foidolite and Variolite belong to Igneous Rocks.Texture of Foidolite is Earthy whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Foidolite appears Dull and Variolite appears Dull and Soft. The luster of Foidolite is subvitreous to dull while that of Variolite is not available. Foidolite is available in black, brown, colourless, green, grey, pink, white colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Foidolite and Variolite are cemetery markers, commemorative tablets, creating artwork.

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