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
  
Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature
  
History
  
  
Origin
Ethiopia
  
Unknown
  
Discoverer
Obsius
  
René Just Haüy
  
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
  
From French, Greek eklogē selection with reference to the selective content of the rock + -ite1
  
Class
Igneous Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Glassy
  
Earthy
  
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
  
Black, Brown, Colourless, Green, Grey, Pink, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Shiny
  
Dull, Banded and Foilated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
Garden Decoration
  
Paving Stone, Garden Decoration
  
Other Architectural Uses
Not Yet Used
  
Curbing
  
Industry
  
  
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
  
Not Yet Used
  
Medical Industry
Surgery
  
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
  
Antiquity Uses
Artifacts, Jewellery
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
  
Creating Artwork, Gemstone
  
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
  
Not Available
  
Features
Blocks negativity, Helps to protect against depression
  
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Not Yet Used
  
Not Yet Used
  
Famous Sculptures
Not Applicable
  
Not Applicable
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Not Yet Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
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.
  
Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.
  
Composition
  
  
Mineral Content
Not Available
  
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Chemical Erosion, Sea Erosion
  
Physical Properties
  
  
Hardness
5-5.5
  
3.5-4
  
Grain Size
Not Applicable
  
Fine Grained
  
Fracture
Conchoidal
  
Not Available
  
Streak
White
  
White
  
Porosity
Very Less Porous
  
Less Porous
  
Luster
Vitreous
  
Subvitreous to Dull
  
Compressive Strength
Not Available
  
Cleavage
Non-Existent
  
Perfect
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
2.6-2.7
  
2.86-2.87
  
Transparency
Translucent
  
Opaque
  
Density
2.6 g/cm3
  
3.2-3.6 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
Afghanistan, Indonesia, Japan, Russia
  
India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey
  
Africa
Kenya
  
Ethiopia, Morocco, South Africa
  
Europe
Greece, Hungary, Iceland, Italy, Turkey
  
France, Germany, Italy, Norway, Scotland
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, Mexico, USA
  
Canada, Costa Rica, Panama, USA
  
South America
Argentina, Chile, Ecuador, Peru
  
Argentina, Brazil, Colombia, Ecuador
  
Deposits in Oceania Continent
  
  
Australia
New Zealand
  
Central Australia, New Zealand, Queensland
  
Obsidian vs Eclogite 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 Eclogite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Eclogite. Learn more about Obsidian vs Eclogite in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Eclogite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Obsidian and Eclogite, 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 Eclogite include Not yet used.
More about Obsidian and Eclogite
Here you can know more about Obsidian and Eclogite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Eclogite consists of mineral content and compound content. The mineral content of Obsidian is not available and mineral content of Eclogite includes Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Eclogite, 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, Eclogite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Obsidian is Shiny and that of Eclogite is Dull, Banded and Foilated. Properties of rock is another aspect for Obsidian vs Eclogite. The hardness of Obsidian is 5-5.5 and that of Eclogite is 3.5-4. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Eclogite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian and Eclogite is white. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Eclogite 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 Eclogite is heat resistant.