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
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
Discoverer
Obsius
Unknown
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black, Brown, Dark Grey to Black, Red
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Glassy and Vesicular
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration
Garden Decoration, Paving Stone
Other Architectural Uses
Not Yet Used
Curbing
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Medical Industry
Surgery
Not Yet Used
Antiquity Uses
Artifacts, Jewellery
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Not Available
Features
Blocks negativity, Helps to protect against depression
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
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
Figurines
Not Yet Used
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.
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
Mineral Content
Not Available
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, NaCl
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
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, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Not Applicable
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Very Less Porous
Highly Porous
Luster
Vitreous
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Non-Existent
Perfect
Toughness
Not Available
2.1
Specific Gravity
2.6-2.7
Not Available
Transparency
Translucent
Opaque
Density
2.6 g/cm3
Not Available
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
Afghanistan, Indonesia, Japan, Russia
Africa
Kenya
Ethiopia, Kenya, Tanzania
Europe
Greece, Hungary, Iceland, Italy, Turkey
Greece, Hungary, Iceland, Italy, Turkey
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
South America
Argentina, Chile, Ecuador, Peru
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand
New Zealand, Western Australia
Obsidian vs Scoria 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 Scoria characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Scoria. Learn more about Obsidian vs Scoria in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Scoria include Decorative aggregates and Interior decoration. Due to some exceptional properties of Obsidian and Scoria, 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 Scoria include Cement manufacture, Construction aggregate, For road aggregate, In landscaping and drainage works.
More about Obsidian and Scoria
Here you can know more about Obsidian and Scoria. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Scoria consists of mineral content and compound content. The mineral content of Obsidian is not available and mineral content of Scoria includes Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Scoria, 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, Scoria is available in black, brown, dark grey to black, red colors. Appearance of Obsidian is Shiny and that of Scoria is Glassy and Vesicular. Properties of rock is another aspect for Obsidian vs Scoria. The hardness of Obsidian is 5-5.5 and that of Scoria is 5-6. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Scoria are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian and Scoria is white. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Scoria 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 Scoria is heat resistant, impact resistant, pressure resistant, wear resistant.