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
Oolite is a sedimentary rock formed from ooids, spherical grains which are composed of concentric layers of calcite
Discoverer
Obsius
William Smith
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From oo- + -lite, after German Oolit. A rock consisting of fine grains of carbonate of lime
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
Black, Blue, Brown, Cream, Green, Grey, Pink, Red, Silver, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Rounded and Rough
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
-
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Cement Manufacture, Cobblestones, Landscaping
Medical Industry
Surgery
-
Antiquity Uses
Artifacts, Jewellery
Artifacts
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Creating Artwork, Jewelry, Used in aquariums
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Pisolitic Oolite and Oncolitic Oolite
Features
Blocks negativity, Helps to protect against depression
Available in lots of colors, Generally rough to touch, Very fine grained rock
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.
Oolites form when layers of calcite are deposited around a sand grain or fossil piece and are rolled around in calm water, which makes them round.
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, Ca, 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
Conchoidal
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Pearly to Shiny
Specific Gravity
2.6-2.7
-9999
Transparency
Translucent
Opaque
Density
2.6 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Wear 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 Oolite Properties
Know all about Obsidian and Oolite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Oolite belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Oolite is Clastic or Non-Clastic. Obsidian appears Shiny and Oolite appears Rounded and Rough. The luster of Obsidian is vitreous while that of Oolite is pearly to shiny. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Oolite is available in black, blue, brown, cream, green, grey, pink, red, silver, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Oolite are creating artwork, jewelry, used in aquariums.