Definition
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Discoverer
Unknown
John Peter Salley
Etymology
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Vesicular
Amorphous, Glassy
Color
Black, Brown, Dark Grey to Black, Red
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Glassy and Vesicular
Veined or Pebbled
Interior Uses
Decorative Aggregates, Interior Decoration
-
Exterior Uses
Garden Decoration, Paving Stone
-
Other Architectural Uses
Curbing
-
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
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
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Types
Basaltic Scoria and Andesitic Scoria
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Formation
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
Coal forms from the accumulation of plant debris in a swamp environment which is buried by sediments such as mud or sand and then compacted to form coal.
Mineral Content
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Analcime, Apatite, Barite, Calcite, Chalcopyrite, Chlorite, Chromite, Clausthalite, Clay Minerals, Crandallite Group, Dolomite, Feldspar, Galena, Gypsum, Marcasite, Muscovite or Illite, Pyrite, Quartz, Siderite, Sphalerite, Zircon
Compound Content
Ca, NaCl
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
-
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Subvitreous to Dull
Dull to Vitreous to Submetallic
Specific Gravity
-9999
1.1-1.4
Transparency
Opaque
Opaque
Density
-9999 g/cm3
1100-1400 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
Ethiopia, Kenya, Tanzania
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
Greece, Hungary, Iceland, Italy, Turkey
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Deposits in Western Continents
North America
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
Canada, Mexico, USA
South America
Argentina, Chile, Ecuador, Peru
Brazil, Chile, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, Queensland, Victoria