Definition
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
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
Discoverer
Unknown
Obsius
Etymology
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Color
Black, Brown, Dark Grey to Black, Red
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Glassy and Vesicular
Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
Garden Decoration
Other Architectural Uses
Curbing
-
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Jewellery
Commercial Uses
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Creating Artwork, Mirror, Used in aquariums
Types
Basaltic Scoria and Andesitic Scoria
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Blocks negativity, Helps to protect against depression
Archaeological Significance
Formation
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
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
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
-
Compound Content
Ca, NaCl
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
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
Fine Grained
-
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Very Less Porous
Luster
Subvitreous to Dull
Vitreous
Specific Gravity
-9999
2.6-2.7
Transparency
Opaque
Translucent
Density
-9999 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
Afghanistan, Indonesia, Japan, Russia
Africa
Ethiopia, Kenya, Tanzania
Kenya
Europe
Greece, Hungary, Iceland, Italy, Turkey
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
Canada, Mexico, USA
South America
Argentina, Chile, Ecuador, Peru
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand
All about Scoria and Obsidian Properties
Know all about Scoria and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Scoria and Obsidian belong to Igneous Rocks.Texture of Scoria is Vesicular whereas that of Obsidian is Glassy. Scoria appears Glassy and Vesicular and Obsidian appears Shiny. The luster of Scoria is subvitreous to dull while that of Obsidian is vitreous. Scoria is available in black, brown, dark grey to black, red colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Scoria are as a traction material on snow-covered roads, creating artwork, high-temperature insulation, in gas barbecue grills and that of Obsidian are creating artwork, mirror, used in aquariums.