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Skarn and Obsidian


Obsidian and Skarn


Definition

Definition
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin   
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   

History
  
  

Origin
USA, Australia   
Ethiopia   

Discoverer
Tornebohm   
Obsius   

Etymology
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.   
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius   

Class
Metamorphic Rocks   
Igneous Rocks   

Sub-Class
Durable Rock, Hard Rock   
Durable Rock, Medium Hardness Rock   

Family
  
  

Group
Not Applicable   
Volcanic   

Other Categories
Fine Grained Rock, Opaque Rock   
Opaque Rock   

Texture

Texture
Earthy, Mud-rich, Rough   
Glassy   

Color
Black, Brown, Colourless, Green, Grey, White   
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow   

Maintenance
Less   
Less   

Durability
Durable   
Durable   

Water Resistant
Yes   
Yes   

Scratch Resistant
Yes   
Yes   

Stain Resistant
No   
No   

Wind Resistant
Yes   
No   

Acid Resistant
Yes   
No   

Appearance
Dull   
Shiny   

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Entryways, Interior Decoration   
Decorative Aggregates, Interior Decoration   

Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone   
Garden Decoration   

Other Architectural Uses
Curbing   
Not Yet Used   

Industry
  
  

Construction Industry
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories   
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points   

Medical Industry
Not Applicable   
Surgery   

Antiquity Uses
Artifacts, Monuments, Sculpture   
Artifacts, Jewellery   

Other Uses
  
  

Commercial Uses
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)   
Creating Artwork, Mirror, Used in aquariums   

Types

Types
Endoskarns   
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian   

Features
Host Rock for Lead, Zinc and Copper Deposits   
Blocks negativity, Helps to protect against depression   

Archaeological Significance
  
  

Monuments
Used   
Not Yet Used   

Famous Monuments
Data Not Available   
Not Applicable   

Sculpture
Used   
Not Yet Used   

Famous Sculptures
Data Not Available   
Not Applicable   

Pictographs
Not Used   
Used   

Petroglyphs
Not Used   
Used   

Figurines
Used   
Not Yet Used   

Fossils
Absent   
Absent   

Formation

Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.   
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.   

Composition
  
  

Mineral Content
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite   
Not Available   

Compound Content
Au, CaO, Carbon Dioxide, Cu, Fe, MgO   
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide   

Transformation
  
  

Metamorphism
Yes   
Yes   

Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism   
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism   

Weathering
No   
Yes   

Types of Weathering
Not Applicable   
Biological Weathering, Chemical Weathering, Mechanical Weathering   

Erosion
No   
Yes   

Types of Erosion
Not Applicable   
Chemical Erosion, Coastal Erosion, Glacier Erosion   

Properties

Physical Properties
  
  

Hardness
6.5   
5-5.5   

Grain Size
Fine Grained   
Not Applicable   

Fracture
Irregular   
Conchoidal   

Streak
Light to dark brown   
White   

Porosity
Less Porous   
Very Less Porous   

Luster
Waxy and Dull   
Vitreous   

Compressive Strength
Not Available   
0.15 N/mm2   
33

Cleavage
Slaty   
Non-Existent   

Toughness
2.4   
Not Available   

Specific Gravity
2.86   
2.6-2.7   

Transparency
Opaque   
Translucent   

Density
2.8-2.9 g/cm3   
2.6 g/cm3   

Thermal Properties
  
  

Specific Heat Capacity
0.92 kJ/Kg K   
10
0.92 kJ/Kg K   
10

Resistance
Heat Resistant   
Heat Resistant, Impact Resistant   

Reserves

Deposits in Eastern Continents
  
  

Asia
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka   
Afghanistan, Indonesia, Japan, Russia   

Africa
South Africa, Western Africa   
Kenya   

Europe
United Kingdom   
Greece, Hungary, Iceland, Italy, Turkey   

Others
Not Yet Found   
Not Yet Found   

Deposits in Western Continents
  
  

North America
Canada   
Canada, Mexico, USA   

South America
Brazil, Colombia, Paraguay   
Argentina, Chile, Ecuador, Peru   

Deposits in Oceania Continent
  
  

Australia
Central Australia, Western Australia   
New Zealand   

Summary >>
<< Reserves

All about Skarn and Obsidian Properties

Know all about Skarn and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Skarn belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks.Texture of Skarn is Earthy, Mud-rich, Rough whereas that of Obsidian is Glassy. Skarn appears Dull and Obsidian appears Shiny. The luster of Skarn is waxy and dull while that of Obsidian is vitreous. Skarn is available in black, brown, colourless, green, grey, white colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo) and that of Obsidian are creating artwork, mirror, used in aquariums.

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