Definition
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
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
Discoverer
Edgar Bailey
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
From Latin varius, speckled, variegated
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Opaque Rock
Texture
Foliated
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Blue, Bluish - Grey, Purple, Shades of Blue
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull and Banded
Dull and Soft
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, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Cemetery Markers, Creating Artwork
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
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.
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
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
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, 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
Types of Weathering
Mechanical Weathering
Biological Weathering, Chemical 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
Highly Porous
Less Porous
Specific Gravity
3-3.2
2.8-3
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.9-3.1 g/cm3
Resistance
Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Japan, Turkey
India, Russia
Africa
Egypt, Ethiopia, South Africa
South Africa
Europe
France, Greece, Iceland
Iceland
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
Blueschist 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. Blueschist vs Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Blueschist and Properties of Variolite. Learn more about Blueschist vs Variolite in the next section. The interior uses of Blueschist include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Blueschist and Variolite, they have various applications in construction industry. The uses of Blueschist in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Blueschist and Variolite
Here you can know more about Blueschist and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Blueschist and Variolite consists of mineral content and compound content. The mineral content of Blueschist includes Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz 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 Blueschist vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Blueschist is available in blue, bluish - grey, purple, shades of blue colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Blueschist is Dull and Banded and that of Variolite is Dull and Soft. Properties of rock is another aspect for Blueschist vs Variolite. The hardness of Blueschist is 3.5-4 and that of Variolite is 6. The types of Blueschist are Metamorphic rock whereas types of Variolite are Metamorphic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Blueschist and Variolite is white to grey. The specific heat capacity of Blueschist is 0.84 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.Blueschist is impact resistant, pressure resistant whereas Variolite is heat resistant, pressure resistant, wear resistant.