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%
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
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, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Dull and Soft
Dull
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
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Metamorphic rock
Igneous rock
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Host Rock for Lead
Archaeological Significance
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.
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Grain Size
-
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
White
Porosity
Less Porous
Very Less Porous
Luster
-
Subvitreous to Dull
Specific Gravity
2.8-3
2.86
Transparency
Opaque
Translucent
Density
2.9-3.1 g/cm3
-9999 g/cm3
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
Deposits in Western Continents
North America
Canada, USA
Canada, USA
Deposits in Oceania Continent
Australia
-
Central Australia, Western Australia
Variolite vs Foidolite 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. Variolite vs Foidolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Foidolite. Learn more about Variolite vs Foidolite in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Foidolite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Variolite and Foidolite, they have various applications in construction industry. The uses of Variolite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Foidolite include As dimension stone, Cement manufacture, For road aggregate.
More about Variolite and Foidolite
Here you can know more about Variolite and Foidolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Foidolite consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Foidolite includes Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Foidolite, the texture, color and appearance plays an important role in determining the type of rock. Variolite is available in black, brown, light to dark grey colors whereas, Foidolite is available in black, brown, green, grey, pink, white colors. Appearance of Variolite is Dull and Soft and that of Foidolite is Dull. Properties of rock is another aspect for Variolite vs Foidolite. The hardness of Variolite is 6 and that of Foidolite is 1.5. The types of Variolite are Metamorphic rock whereas types of Foidolite are Igneous rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Variolite is white to grey while that of Foidolite is white. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Foidolite is 0.79 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Variolite is heat resistant, pressure resistant, wear resistant whereas Foidolite is heat resistant, wear resistant.