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Phonolite and Variolite


Variolite and Phonolite


Definition

Definition
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic   
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 Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit   
From Latin varius, speckled, variegated   

Class
Igneous Rocks   
Igneous Rocks   

Sub-Class
Durable Rock, Medium Hardness Rock   
Durable Rock, Hard Rock   

Family
  
  

Group
Not Applicable   
Volcanic   

Other Categories
Fine Grained Rock, Opaque Rock   
Opaque Rock   

Texture

Texture
Granular   
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular   

Color
Brown, Buff, Cream, Green, Grey, Pink, White   
Black, Brown, Light to Dark Grey   

Maintenance
Less   
Less   

Durability
Durable   
Durable   

Water Resistant
Yes   
Yes   

Scratch Resistant
Yes   
Yes   

Stain Resistant
Yes   
No   

Wind Resistant
No   
No   

Acid Resistant
Yes   
Yes   

Appearance
Banded and Foilated   
Dull and Soft   

Uses

Architecture
  
  

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

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

Other Architectural Uses
Curbing   
Curbing   

Industry
  
  

Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics   
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone   

Medical Industry
Not Yet Used   
Not Yet Used   

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

Other Uses
  
  

Commercial Uses
Cemetery Markers, Creating Artwork   
Cemetery Markers, Creating Artwork   

Types

Types
Kenyte   
Not Available   

Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock   
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
Phonolite are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.   
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
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite   
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, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide   

Transformation
  
  

Metamorphism
Yes   
Yes   

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

Weathering
Yes   
Yes   

Types of Weathering
Chemical Weathering, Mechanical Weathering   
Biological Weathering, Chemical Weathering, Mechanical Weathering   

Erosion
Yes   
No   

Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion   
Not Applicable   

Properties

Physical Properties
  
  

Hardness
5.5-6   
6   

Grain Size
Fine Grained   
Not Applicable   

Fracture
Conchoidal to Uneven   
Conchoidal   

Streak
White   
White to Grey   

Porosity
Less Porous   
Less Porous   

Luster
Greasy to Dull   
Not Available   

Compressive Strength
150.00 N/mm2   
14
37.50 N/mm2   
27

Cleavage
Poor   
Not Available   

Toughness
Not Available   
2.3   

Specific Gravity
2.6   
2.8-3   

Transparency
Translucent to Opaque   
Opaque   

Density
2.6 g/cm3   
2.9-3.1 g/cm3   

Thermal Properties
  
  

Specific Heat Capacity
Not Available   
0.84 kJ/Kg K   
15

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

Reserves

Deposits in Eastern Continents
  
  

Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam   
India, Russia   

Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa   
South Africa   

Europe
Andorra, Finland, France, Germany, Great Britain, Italy, Norway, Portugal, Spain, Sweden   
Iceland   

Others
Greenland   
Not Yet Found   

Deposits in Western Continents
  
  

North America
Canada, USA   
Canada, USA   

South America
Brazil, Chile, Colombia, Uruguay, Venezuela   
Brazil   

Deposits in Oceania Continent
  
  

Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia   
Not Yet Found   

Summary >>
<< Reserves

All about Phonolite and Variolite Properties

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

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