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
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Discoverer
Unknown
Edgar Bailey
Etymology
From Latin varius, speckled, variegated
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Foliated
Color
Black, Brown, Light to Dark Grey
Blue, Bluish - Grey, Purple, Shades of Blue
Durability
Durable
Durable
Appearance
Dull and Soft
Dull and Banded
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
Garden Decoration, Office Buildings
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
-
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Types
Metamorphic rock
Metamorphic rock
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Has High structural resistance against erosion and climate, Very fine grained rock
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.
Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.
Mineral Content
Olivine, Plagioclase, Pyroxene
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
-
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
White to Grey
Porosity
Less Porous
Highly Porous
Specific Gravity
2.8-3
3-3.2
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
Japan, Turkey
Africa
South Africa
Egypt, Ethiopia, South Africa
Europe
Iceland
France, Greece, Iceland
Deposits in Western Continents
North America
Canada, USA
USA
Deposits in Oceania Continent
Variolite vs Blueschist 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 Blueschist characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Blueschist. Learn more about Variolite vs Blueschist in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Blueschist include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Variolite and Blueschist, 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 Blueschist include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Variolite and Blueschist
Here you can know more about Variolite and Blueschist. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Blueschist consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Blueschist includes Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Blueschist, 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, Blueschist is available in blue, bluish - grey, purple, shades of blue colors. Appearance of Variolite is Dull and Soft and that of Blueschist is Dull and Banded. Properties of rock is another aspect for Variolite vs Blueschist. The hardness of Variolite is 6 and that of Blueschist is 3.5-4. The types of Variolite are Metamorphic rock whereas types of Blueschist are Metamorphic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Variolite and Blueschist is white to grey. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Blueschist 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.Variolite is heat resistant, pressure resistant, wear resistant whereas Blueschist is impact resistant, pressure resistant.