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
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
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Aphanitic to Porphyritic
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Bluish - Grey, Grey, Pink, Yellow
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull and Soft
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
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
Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork
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
Famous Monuments
Middle of the Earth in Ecuador
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
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.
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
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
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Not Applicable
Grain Size
Very fine-grained
Not Applicable
Fracture
Uneven
Conchoidal
Streak
White
White to Grey
Porosity
Less Porous
Less Porous
Luster
Vitreous
Not Available
Cleavage
Not Available
Not Available
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
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
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
Andesite vs Variolite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Andesite vs Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Andesite and Properties of Variolite. Learn more about Andesite vs Variolite in the next section. The interior uses of Andesite include Decorative aggregates, Floor tiles, Homes, Interior decoration and Kitchens whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Andesite and Variolite, they have various applications in construction industry. The uses of Andesite in construction industry include Cobblestones, Construction aggregate, For road aggregate and that of Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Andesite and Variolite
Here you can know more about Andesite and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Andesite and Variolite consists of mineral content and compound content. The mineral content of Andesite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon and mineral content of Variolite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Andesite vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Andesite is available in bluish - grey, grey, pink, yellow colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Andesite is Dull and Soft and that of Variolite is Dull and Soft. Properties of rock is another aspect for Andesite vs Variolite. The hardness of Andesite is 7 and that of Variolite is 6. The types of Andesite are Icelandite whereas types of Variolite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Andesite is white while that of Variolite is white to grey. The specific heat capacity of Andesite is 2.39 kJ/Kg K and that of Variolite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Andesite is heat resistant, pressure resistant, wear resistant whereas Variolite is heat resistant, pressure resistant, wear resistant.