Definition
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Discoverer
Unknown
Unknown
Etymology
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
From German Tachylite, from tachy- + Greek lutos soluble, melting
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Vesicular
Vitreous
Color
Black, Brown, Dark Grey to Black, Red
Black, Dark Brown
Durability
Durable
Durable
Appearance
Glassy and Vesicular
Glassy
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Cutting Tool, Knives, Landscaping, Scrapers
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Cemetery Markers, Creating Artwork
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Available in Lots of Colors and Patterns, Clasts are smooth to touch, NA
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
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
Tachylite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Feldspar, Olivine
Compound Content
Ca, NaCl
Fe, Mg
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional 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, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Subvitreous to Dull
Resinous
Compressive Strength
Not Available
Cleavage
Perfect
Not Available
Toughness
2.1
Not Available
Specific Gravity
Not Available
2.4
Transparency
Opaque
Opaque
Density
Not Available
3.058 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
Cambodia, Russia, South Korea
Africa
Ethiopia, Kenya, Tanzania
East Africa
Europe
Greece, Hungary, Iceland, Italy, Turkey
England, Germany, Hungary, Iceland, Scotland, Sweden
Others
Not Yet Found
Hawaii Islands
Deposits in Western Continents
North America
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
USA
South America
Argentina, Chile, Ecuador, Peru
Not Yet Found
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Victoria