Definition
Ijolite is an intrusive igneous rock which is composed mainly of nepheline and an alkali pyroxene, usually aegirine-augite
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
Origin
Finland, Europe
Ethiopia
Discoverer
Unknown
Obsius
Etymology
From the first syllable of the Finnish words Ii-vaara, Iijoki, &c. commonly used geographical names in Finland, and the Gr. Xiflos, a stone
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Opaque Rock
Texture
Earthy, Granular
Glassy
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded and Foilated
Shiny
Interior Uses
Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Interior Decoration, Kitchens
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Garden Decoration
Other Architectural Uses
Curbing
-
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Mirror, Used in aquariums
Types
Alkaline rock
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Is one of the oldest rock
Blocks negativity, Helps to protect against depression
Archaeological Significance
Formation
Ijolite 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.
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.
Mineral Content
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
-
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Coarse Grained
-
Fracture
Conchoidal to Uneven
Conchoidal
Porosity
Less Porous
Very Less Porous
Luster
Greasy to Dull
Vitreous
Specific Gravity
2.6-2.76
2.6-2.7
Transparency
Opaque
Translucent
Density
2.6 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Afghanistan, Indonesia, Japan, Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Kenya
Europe
England, Finland, Germany, Great Britain, Greece, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Colombia
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
New Zealand
All about Ijolite and Obsidian Properties
Know all about Ijolite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Ijolite and Obsidian belong to Igneous Rocks.Texture of Ijolite is Earthy, Granular whereas that of Obsidian is Glassy. Ijolite appears Banded and Foilated and Obsidian appears Shiny. The luster of Ijolite is greasy to dull while that of Obsidian is vitreous. Ijolite is available in brown, buff, cream, green, grey, pink, white colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Ijolite are cemetery markers, creating artwork and that of Obsidian are creating artwork, mirror, used in aquariums.