Definition
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Discoverer
Obsius
Edgar Bailey
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Volcanic
Not Applicable
Other Categories
Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Blue, Bluish - Grey, Purple, Shades of Blue
Durability
Durable
Durable
Appearance
Shiny
Dull and Banded
Interior Uses
Decorative Aggregates, Interior Decoration
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
Garden Decoration
Garden Decoration, Office Buildings
Other Architectural Uses
Not Yet Used
Not Yet Used
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Surgery
Not Yet Used
Antiquity Uses
Artifacts, Jewellery
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Not Available
Features
Blocks negativity, Helps to protect against depression
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Figurines
Not Yet Used
Used
Formation
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
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
Not Available
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
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Not Applicable
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
White
White to Grey
Porosity
Very Less Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Non-Existent
Slaty
Toughness
Not Available
1.5
Specific Gravity
2.6-2.7
3-3.2
Transparency
Translucent
Opaque
Density
2.6 g/cm3
2.8-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
Japan, Turkey
Africa
Kenya
Egypt, Ethiopia, South Africa
Europe
Greece, Hungary, Iceland, Italy, Turkey
France, Greece, Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Argentina, Chile, Ecuador, Peru
Not Yet Found
Deposits in Oceania Continent
Australia
New Zealand
New Zealand
Obsidian 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. Obsidian vs Blueschist characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Blueschist. Learn more about Obsidian vs Blueschist in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Blueschist include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Obsidian and Blueschist, they have various applications in construction industry. The uses of Obsidian in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Blueschist include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Obsidian and Blueschist
Here you can know more about Obsidian and Blueschist. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Blueschist consists of mineral content and compound content. The mineral content of Obsidian is not available 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 Obsidian vs Blueschist, the texture, color and appearance plays an important role in determining the type of rock. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas, Blueschist is available in blue, bluish - grey, purple, shades of blue colors. Appearance of Obsidian is Shiny and that of Blueschist is Dull and Banded. Properties of rock is another aspect for Obsidian vs Blueschist. The hardness of Obsidian is 5-5.5 and that of Blueschist is 3.5-4. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Blueschist are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian is white while that of Blueschist is white to grey. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Blueschist is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Obsidian is heat resistant, impact resistant whereas Blueschist is impact resistant, pressure resistant.