Definition
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
  
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
  
History
  
  
Discoverer
Unknown
  
Alexandre Brongniart and René Just Haüy
  
Etymology
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
  
From Greek trakhus rough’ or trakhutēs roughness
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Volcanic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Vesicular
  
Aphanitic to Porphyritic
  
Color
Black, Brown, Dark Grey to Black, Red
  
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
  
Maintenance
More
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Glassy and Vesicular
  
Banded
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Exterior Uses
Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
  
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
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, Is one of the oldest rock, Matrix variable
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
  
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.
  
Composition
  
  
Mineral Content
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
  
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
  
Compound Content
Ca, NaCl
  
Potassium Oxide, Sodium Oxide, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
5-6
  
6
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Not Available
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Subvitreous to Dull
  
Metallic
  
Compressive Strength
Not Available
  
150.00 N/mm
2
  
14
Cleavage
Perfect
  
Not Available
  
Toughness
2.1
  
Not Available
  
Specific Gravity
Not Available
  
2.7
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.43-2.45 g/cm3
  
Thermal Properties
  
  
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Afghanistan, Indonesia, Japan, Russia
  
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
  
Africa
Ethiopia, Kenya, Tanzania
  
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
  
Europe
Greece, Hungary, Iceland, Italy, Turkey
  
Bulgaria, England, Germany, Norway, Romania, Switzerland
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
  
USA
  
South America
Argentina, Chile, Ecuador, Peru
  
Brazil, Chile
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Western Australia
  
New Zealand, Queensland, South Australia, Western Australia