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
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Durable Rock, Medium Hardness Rock
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Decorative Aggregates, Interior Decoration
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Creating Artwork, Mirror, Used in aquariums
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Blocks negativity, Helps to protect against depression
Archaeological Significance
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.
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Erosion, Coastal Erosion, Glacier Erosion
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Afghanistan, Indonesia, Japan, Russia
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Learn more about Properties of Obsidian
What is Obsidian? In this section, we will learn more about properties of Obsidian i.e. physical and thermal properties. Physical properties of Obsidian include Color, Streak, Hardness, Structure, Cleavage, Fracture, Luster, Specific Gravity etc. The strength of Obsidian is 0.15 N/mm2. Streak of Obsidian is white while its cleavage is . Luster of Obsidian is vitreous and its fracture is conchoidal. Obsidian is translucent in nature. Know all about Obsidian, What is Obsidian, its composition, features, facts and reserves in next sections.
Know about Composition of Obsidian
What is Obsidian composed of? Get to know about composition of Obsidian here. Obsidian definition gives information about the Formation of Obsidian and its composition.The composition of Obsidian can be further divided into mineral and compound content. The mineral content of Obsidian rock includes and The compound content of Obsidian rock includes Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide. Almost all rocks undergo transformation process. Know all about Obsidian rock in next section.