Definition
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
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
New Zealand
Ethiopia
Discoverer
Unknown
Obsius
Etymology
From Greek mulōn mill + -ite
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Color
Black to Grey
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Garden Decoration
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
for Road Aggregate, Landscaping, Roadstone
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
Not Yet Used
Surgery
Antiquity Uses
Artifacts, Monuments
Artifacts, Jewellery
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Creating Artwork, Mirror, Used in aquariums
Types
Blastomylonites, Ultramylonites and Phyllonites
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Surfaces are often shiny
Blocks negativity, Helps to protect against depression
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
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
Porphyroblasts
Not Available
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Not Applicable
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Very Less Porous
Cleavage
Conchoidal
Non-Existent
Toughness
Not Available
Not Available
Specific Gravity
2.97-3.05
2.6-2.7
Transparency
Opaque
Translucent
Density
2.6-4.8 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
Afghanistan, Indonesia, Japan, Russia
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Kenya
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
Not Yet Found
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New Zealand
All about Mylonite and Obsidian Properties
Know all about Mylonite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Mylonite belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks.Texture of Mylonite is Foliated whereas that of Obsidian is Glassy. Mylonite appears Dull, Banded and Foilated and Obsidian appears Shiny. The luster of Mylonite is shiny while that of Obsidian is vitreous. Mylonite is available in black to grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Mylonite are creating artwork, gemstone, jewelry and that of Obsidian are creating artwork, mirror, used in aquariums.