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
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Discoverer
Unknown
Unknown
Etymology
From Latin varius, speckled, variegated
from French néphéline, from Greek nephelē
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Aphanitic
Color
Black, Brown, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Skeletal
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Not Available
Peralkaline Nephelinite
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
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.
Nephelinite 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
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Not Applicable
Fine Grained
Streak
White to Grey
White
Porosity
Less Porous
Less Porous
Luster
Not Available
Vitreous to Metallic
Cleavage
Not Available
Imperfect
Specific Gravity
2.8-3
2.4-2.9
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Africa
South Africa
Rwanda, Tanzania
Europe
Iceland
Not Yet Found
Others
Not Yet Found
Hawaii Islands
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Colombia
Deposits in Oceania Continent
Australia
Not Yet Found
Not Yet Found
Variolite vs Nephelinite 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 Nephelinite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Nephelinite. Learn more about Variolite vs Nephelinite in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Variolite and Nephelinite, 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 Nephelinite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate.
More about Variolite and Nephelinite
Here you can know more about Variolite and Nephelinite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Nephelinite consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Nephelinite includes Clinopyroxene, Nepheline, Plagioclase. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Nephelinite, 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, Nephelinite is available in black, brown, colourless, green, grey, white colors. Appearance of Variolite is Dull and Soft and that of Nephelinite is Skeletal. Properties of rock is another aspect for Variolite vs Nephelinite. The hardness of Variolite is 6 and that of Nephelinite is 6.5. The types of Variolite are Not Available whereas types of Nephelinite are Peralkaline Nephelinite. 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 Nephelinite is white. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Nephelinite is 0.88 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 Nephelinite is heat resistant.