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
Basanite is a black basaltic rock which mainly contains plagioclase, augite, olivine and nepheline and is formerly used as a touchstone
Discoverer
Obsius
Unknown
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From Latin basanites + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy
Aphanitic to Porphyritic
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Glassy or Pearly
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
Garden Decoration
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
-
Whetstones
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Surgery
-
Antiquity Uses
Artifacts, Jewellery
Artifacts, Monuments
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
As a touchstone, Creating Artwork, Gemstone, In fire-starting tools, Manufacture of tools, Metallurgical Flux, Jewelry, To ignite fire, Used in flintlock firearms
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Nepheline-Basanite, Analcite-Basanite and Leucite-Basanite
Features
Blocks negativity, Helps to protect against depression
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate, Used as a touchstone
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.
Basanite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes.
Mineral Content
-
Augite, Feldspar, Ilmenite, Olivine, Plagioclase
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Potassium Oxide, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
-
Fine Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Very Less Porous
Highly Porous
Luster
Vitreous
Waxy and Dull
Specific Gravity
2.6-2.7
2.5-2.8
Transparency
Translucent
Translucent to Opaque
Density
2.6 g/cm3
2.7 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
-
Europe
Greece, Hungary, Iceland, Italy, Turkey
Germany, Hungary, Italy, Spain
Others
-
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Argentina, Chile, Ecuador, Peru
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New Zealand
New South Wales, New Zealand, Queensland, South Australia, Western Australia
All about Obsidian and Basanite Properties
Know all about Obsidian and Basanite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Basanite belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Basanite is Aphanitic to Porphyritic. Obsidian appears Shiny and Basanite appears Glassy or Pearly. The luster of Obsidian is vitreous while that of Basanite is waxy and dull. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Basanite is available in black, brown, green, grey, red, white colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Basanite are as a touchstone, creating artwork, gemstone, in fire-starting tools, manufacture of tools, metallurgical flux, jewelry, to ignite fire, used in flintlock firearms.