Obsidian and Mugearite
Definition
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
Mugearite is a type of oligoclase bearing basalt, also comprising of olivine, apatite, and opaque oxides
History
Origin
Ethiopia
Skye, Scotland
Discoverer
Obsius
Alfred Harker
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From mugear + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Opaque Rock
Opaque Rock
Texture
Texture
Glassy
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black, Brown, Light to Dark Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
No
Yes
Wind Resistant
No
No
Acid Resistant
No
No
Appearance
Shiny
Dull and Soft
Uses
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Floor Tiles, Flooring, Homes, Hotels
Exterior Uses
Garden Decoration
As Building Stone, Garden Decoration
Other Architectural Uses
Not Yet Used
Curbing
Industry
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Surgery
Not Yet Used
Antiquity Uses
Artifacts, Jewellery
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Creating Artwork
Types
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Features
Blocks negativity, Helps to protect against depression
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Used
Petroglyphs
Used
Used
Figurines
Not Yet Used
Used
Fossils
Absent
Absent
Formation
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.
Mugearite forms when lava reaches the Earth's surface near an active volcano. The temperature of lava is between 1100 to 1250° C when it gets to the surface.
Composition
Mineral Content
Not Available
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
Yes
Yes
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Impact Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
Yes
No
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Not Applicable
Properties
Physical Properties
Hardness
5-5.5
6
Grain Size
Not Applicable
Not Applicable
Fracture
Conchoidal
Conchoidal
Streak
White
White to Grey
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Not Available
Compressive Strength
0.15 N/mm2
33
37.50 N/mm2
27
Cleavage
Non-Existent
Not Applicable
Toughness
Not Available
2.3
Specific Gravity
2.6-2.7
2.8-3
Transparency
Translucent
Opaque
Density
2.6 g/cm3
2.9-3.1 g/cm3
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K
10
0.84 kJ/Kg K
15
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Reserves
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
India, Russia
Africa
Kenya
South Africa
Europe
Greece, Hungary, Iceland, Italy, Turkey
Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Argentina, Chile, Ecuador, Peru
Brazil
Deposits in Oceania Continent
Australia
New Zealand
Not Yet Found
All about Obsidian and Mugearite Properties
Know all about Obsidian and Mugearite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Mugearite belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Mugearite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Obsidian appears Shiny and Mugearite appears Dull and Soft. The luster of Obsidian is vitreous while that of Mugearite is not available. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Mugearite is available in black, brown, light to dark grey colors. The commercial uses of Obsidian and Mugearite are creating artwork, mirror, used in aquariums.
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