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
Limestone is a sedimentary rock composed mostly of calcite and aragonite, which are different crystal forms of calcium carbonate
Origin
Ethiopia
New Zealand
Discoverer
Obsius
Belsazar Hacquet
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From lime and stone in late 14th Century
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy
Clastic or Non-Clastic
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Beige, Black, Blue, Brown, Cream, Gold, Green, Grey, Light Green, Light Grey, Linen, Pink, Red, Rust, Silver, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Rough and Banded
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
-
Curbing
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Cement Manufacture, Cobblestones, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar, Roadstone, Source of calcium
Medical Industry
Surgery
In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
Antiquity Uses
Artifacts, Jewellery
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Animal feed filler, As a Feed Additive for Livestock, Paper Industry, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Used in aquariums, Whiting material in toothpaste, paint and paper
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Chalk, Coquina, Fossiliferous Limestone, Lithographic Limestone, Oolitic Limestone, Travertine, Tufa
Features
Blocks negativity, Helps to protect against depression
Host Rock for Lead, Stalactites and stalagmites are formed from this rock, Zinc and Copper Deposits
Archaeological Significance
Famous Monuments
-
Acropolis of Athens in Greece, Agia Sophia in Istanbul, Turkey, Al Aqsa Mosque in Jerusalem, Angkor Wat in Cambodia, Big Ben in London, Charminar in Hyderabad, India, Chhatrapati Shivaji Terminus in Maharashtra, India, Chichen Itza in Mexico, Empire State Building in New York, Khajuraho Temples, India, Kremlin in Moscow, Louvre in Paris, France, Neuschwanstein in Bavaria, Potala Palace in Lahasa, Tibet, Wailing Wall in Jerusalem
Famous Sculptures
-
Ajanta Caves in Maharashtra, India, Elephanta Caves in Maharashtra, India
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.
Limestone is a sedimentary rock which is mainly made up of calcium carbonate.
Mineral Content
-
Calcite, Chert, Clay, Dolomite, Quartz, Sand, Silt
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, Iron(III) Oxide, FeO, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion
Grain Size
-
Fine Grained
Fracture
Conchoidal
Splintery
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Dull to Pearly
Specific Gravity
2.6-2.7
2.3-2.7
Transparency
Translucent
Opaque
Density
2.6 g/cm3
2.3-2.7 g/cm3
Resistance
Heat Resistant, Impact Resistant
Pressure Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Kenya
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
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
Deposits in Oceania Continent
Australia
New Zealand
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
All about Obsidian and Limestone Properties
Know all about Obsidian and Limestone properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Limestone belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Limestone is Clastic or Non-Clastic. Obsidian appears Shiny and Limestone appears Rough and Banded. The luster of Obsidian is vitreous while that of Limestone is dull to pearly. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Limestone is available in beige, black, blue, brown, cream, gold, green, grey, light green, light grey, linen, pink, red, rust, silver, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Limestone are animal feed filler, as a feed additive for livestock, paper industry, raw material for manufacture of quicklime, slaked lime, soil conditioner, used in aquariums, whiting material in toothpaste, paint and paper.