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
A water-soluble mineral sediment resulting from concentration and crystallization by evaporation from an aqueous solution
Discoverer
Obsius
Usiglio
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From a sediment left after the evaporation
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Green, Grey, Silver, White
Durability
Durable
Durable
Appearance
Shiny
Glassy, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
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, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Surgery
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Jewellery
Artifacts
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Used in the manufacture of Ceramic Powder, Used in the preparation of Sulfuric Acid and Silicon Diborite
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Sedimentary rock
Features
Blocks negativity, Helps to protect against depression
Generally rough to touch, Splintery, Veined
Archaeological Significance
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.
Evaporite is water-soluble mineral sediment which forms from concentration and crystallization by evaporation from an aqueous solution.
Mineral Content
-
Calcite, Cancrinite, Gypsum, Kyanite, Magnetite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
CaMg(CO3)2, CaO, Calcium Sulfate, KCl, MgO, NaCl
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
-
Grain Size
-
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Subvitreous to Dull
Specific Gravity
2.6-2.7
2.86-2.99
Transparency
Translucent
Translucent
Density
2.6 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
-
Europe
Greece, Hungary, Iceland, Italy, Turkey
United Kingdom
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Argentina, Chile, Ecuador, Peru
Colombia, Paraguay
Deposits in Oceania Continent
Australia
New Zealand
Central Australia, Western Australia
All about Obsidian and Evaporite Properties
Know all about Obsidian and Evaporite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Evaporite belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Evaporite is Earthy. Obsidian appears Shiny and Evaporite appears Glassy, Vesicular and Foilated. The luster of Obsidian is vitreous while that of Evaporite is subvitreous to dull. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Evaporite is available in green, grey, silver, white colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Evaporite are used in the manufacture of ceramic powder, used in the preparation of sulfuric acid and silicon diborite.