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
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
  
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
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
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
  
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
  
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
  
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
  
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.