Andesite and Variolite
Definition
Definition
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
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
North America
France
Discoverer
Unknown
Unknown
Etymology
From Andes mountains, where it is found in abundance
From Latin varius, speckled, variegated
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Texture
Aphanitic to Porphyritic
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Bluish - Grey, Grey, Pink, Yellow
Black, Brown, Light to Dark Grey
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
No
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
Yes
No
Wind Resistant
No
No
Acid Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
Uses
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
Office Buildings, Roof Tiles
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Cobblestones, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork
Types
Types
Icelandite
Not Available
Features
Generally rough to touch, High silica content, 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
Middle of the Earth in Ecuador
Data Not Available
Sculpture
Used
Used
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Used
Used
Fossils
Absent
Absent
Formation
Formation
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
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, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Olivine, Plagioclase, Pyroxene
Compound Content
Silicon 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
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
Yes
No
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Not Applicable
Properties
Physical Properties
Hardness
7
6
Grain Size
Very fine-grained
Not Applicable
Fracture
Uneven
Conchoidal
Streak
White
White to Grey
Porosity
Less Porous
Less Porous
Luster
Vitreous
Not Available
Compressive Strength
225.00 N/mm2
7
37.50 N/mm2
27
Cleavage
Not Available
Not Available
Toughness
1.1
2.3
Specific Gravity
2.5-2.8
2.8-3
Transparency
Opaque
Opaque
Density
2.11-2.36 g/cm3
2.9-3.1 g/cm3
Thermal Properties
Specific Heat Capacity
2.39 kJ/Kg K
2
0.84 kJ/Kg K
15
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Reserves
Deposits in Eastern Continents
Asia
India, Indonesia, Japan, Nepal, South Korea
India, Russia
Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
South Africa
Europe
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Mexico, USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
Not Yet Found
All about Andesite and Variolite Properties
Know all about Andesite and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Andesite and Variolite belong to Igneous Rocks.Texture of Andesite is Aphanitic to Porphyritic whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Andesite appears Dull and Soft and Variolite appears Dull and Soft. The luster of Andesite is vitreous while that of Variolite is not available. Andesite is available in bluish - grey, grey, pink, yellow colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Andesite are commemorative tablets, creating artwork and that of Variolite are cemetery markers, creating artwork.
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