Definition
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
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
Discoverer
Unknown
Obsius
Etymology
From 17th century, because of its greasy feel and use like a soap
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Color
Black, Black to Grey, Green, Grey
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Appearance
Dull, Banded and Foilated
Shiny
Interior Uses
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Facing Stone, Garden Decoration
Garden Decoration
Other Architectural Uses
Curbing
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Construction Industry
Manufacture of Magnesium and Dolomite Refractories
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
Taken as a Supplement for Calcium or Magnesium
Surgery
Antiquity Uses
Artifacts, Jewellery, Monuments, Sculpture
Artifacts, Jewellery
Commercial Uses
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
Creating Artwork, Mirror, Used in aquariums
Types
Metamorphic rock
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Host Rock for Lead
Blocks negativity, Helps to protect against depression
Archaeological Significance
Famous Monuments
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
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Formation
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
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.
Mineral Content
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
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Compound Content
CaO, Mg, MgO
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
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
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Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
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Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
-
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Very Less Porous
Specific Gravity
2.86
2.6-2.7
Transparency
Opaque
Translucent
Density
2.8-2.9 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Afghanistan, Indonesia, Japan, Russia
Africa
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Kenya
Europe
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Colombia
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Central Australia, New Zealand, Queensland
New Zealand
All about Soapstone and Obsidian Properties
Know all about Soapstone and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Soapstone belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks.Texture of Soapstone is Polished whereas that of Obsidian is Glassy. Soapstone appears Dull, Banded and Foilated and Obsidian appears Shiny. The luster of Soapstone is greasy while that of Obsidian is vitreous. Soapstone is available in black, black to grey, green, grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Soapstone are cemetery markers, creating artwork, gemstone, jewelry, manufacture of soap, solvents, dyes, plastics and fibres, production of lime, source of magnesia (mgo) and that of Obsidian are creating artwork, mirror, used in aquariums.