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
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
Origin
Ethiopia
Webster, North Carolina
Discoverer
Obsius
Unknown
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From the town of Webster located in North Carolina
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Glassy
Clastic, Granular, Phaneritic, Porphyritic
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Interior Decoration
Exterior Uses
Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Not Yet Used
Curbing
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Surgery
Not Yet Used
Antiquity Uses
Artifacts, Jewellery
Artifacts
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Not Available
Features
Blocks negativity, Helps to protect against depression
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Not Yet Used
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.
Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.
Mineral Content
Not Available
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, 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, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Grain Size
Not Applicable
Coarse Grained
Fracture
Conchoidal
Uneven
Streak
White
White, Greenish White or Grey
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Dull to Vitreous to Submetallic
Compressive Strength
Not Available
Cleavage
Non-Existent
Irregular
Toughness
Not Available
Not Available
Specific Gravity
2.6-2.7
3.2-3.5
Transparency
Translucent
Opaque
Density
2.6 g/cm3
3.1-3.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
India, Russia
Africa
Kenya
South Africa
Europe
Greece, Hungary, Iceland, Italy, Turkey
Germany, Greece, Italy, Scotland, Turkey
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Argentina, Chile, Ecuador, Peru
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New Zealand
New Zealand, Queensland
Obsidian vs Websterite 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 Websterite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Websterite. Learn more about Obsidian vs Websterite in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Websterite include Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring and Interior decoration. Due to some exceptional properties of Obsidian and Websterite, 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 Websterite include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Obsidian and Websterite
Here you can know more about Obsidian and Websterite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Websterite consists of mineral content and compound content. The mineral content of Obsidian is not available and mineral content of Websterite includes Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Websterite, 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, Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. Appearance of Obsidian is Shiny and that of Websterite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Obsidian vs Websterite. The hardness of Obsidian is 5-5.5 and that of Websterite is 7. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Websterite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian is white while that of Websterite is white, greenish white or grey. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Websterite is Not Available. 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 Websterite is impact resistant, pressure resistant, wear resistant.