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
Icelandite belongs to volcanic igneous rocks which is rich in iron and belongs to andesite rock
Discoverer
Obsius
Ian S. E. Carmichael
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From its origin place near Cenozoic volcano near the parsonage Þingmúli in East Iceland
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
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Dull and Soft
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
Garden Decoration
Office Buildings, Roof Tiles
Other Architectural Uses
-
Curbing
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Surgery
-
Antiquity Uses
Artifacts, Jewellery
Artifacts, Jewellery, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Cemetery Markers, Creating Artwork
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Intermediate volcanic rock
Features
Blocks negativity, Helps to protect against depression
Generally rough to touch, High silica content, Is one of the oldest 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.
Icelandite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
-
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
-
Very fine-grained
Fracture
Conchoidal
Uneven
Porosity
Very Less Porous
Less Porous
Specific Gravity
2.6-2.7
2.5-2.8
Transparency
Translucent
Opaque
Density
2.6 g/cm3
2.11-2.36 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
India, Indonesia, Japan, Nepal, South Korea
Africa
Kenya
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Europe
Greece, Hungary, Iceland, Italy, Turkey
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Deposits in Western Continents
North America
Canada, Mexico, USA
Mexico, USA
South America
Argentina, Chile, Ecuador, Peru
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand
New South Wales, New Zealand, Western Australia
Obsidian vs Icelandite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Obsidian vs Icelandite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Icelandite. Learn more about Obsidian vs Icelandite in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Icelandite include Decorative aggregates, Floor tiles, Homes, Interior decoration and Kitchens. Due to some exceptional properties of Obsidian and Icelandite, they have various applications in construction industry. The uses of Obsidian in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Icelandite include Cobblestones, Construction aggregate, For road aggregate.
More about Obsidian and Icelandite
Here you can know more about Obsidian and Icelandite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Icelandite consists of mineral content and compound content. The mineral content of Obsidian includes and mineral content of Icelandite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Icelandite, the texture, color and appearance plays an important role in determining the type of rock. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas, Icelandite is available in bluish - grey, grey, pink, yellow colors. Appearance of Obsidian is Shiny and that of Icelandite is Dull and Soft. Properties of rock is another aspect for Obsidian vs Icelandite. The hardness of Obsidian is 5-5.5 and that of Icelandite is 7. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Icelandite are Intermediate volcanic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian and Icelandite is white. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Icelandite is 2.39 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Obsidian is heat resistant, impact resistant whereas Icelandite is heat resistant, pressure resistant, scratch resistant, wear resistant.