Obsidian and Hawaiite
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
Hawaiite is volcanic rock that resembles basalt. It is an olivine basalt with intermediate composition between alkali olivine and mugearite
History
Origin
Ethiopia
Hawaii Islands
Discoverer
Obsius
Joseph Iddings
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From Hawaii Islands
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
No
Wind Resistant
No
Yes
Acid Resistant
No
No
Appearance
Shiny
Dull and Soft
Uses
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
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
Other Uses
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Creating Artwork, Sea Defence
Types
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Not Available
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
Easter Island in the Polynesian Triangle, Pacific Ocean
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Used
Used
Petroglyphs
Used
Used
Figurines
Not Yet Used
Not Yet 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.
Hawaiite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes and reach the Earth's 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
Impact Metamorphism
Weathering
Yes
Yes
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological 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
Not Available
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Not Available
Compressive Strength
0.15 N/mm2
33
37.40 N/mm2
28
Cleavage
Non-Existent
Not Applicable
Toughness
Not Available
Not Available
Specific Gravity
2.6-2.7
Not Available
Transparency
Translucent
Opaque
Density
2.6 g/cm3
Not Available
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K
10
Not Available
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
Hawaii Islands
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 Hawaiite Properties
Know all about Obsidian and Hawaiite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Hawaiite belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Hawaiite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Obsidian appears Shiny and Hawaiite appears Dull and Soft. The luster of Obsidian is vitreous while that of Hawaiite is not available. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Hawaiite is available in black, brown, light to dark grey colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Hawaiite are creating artwork, sea defence.
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