Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Rhyolite is a fine-grained igneous rock which is rich in silica
Discoverer
John Peter Salley
Ferdinand von Richthofen
Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
From German Rhyolit, from Greek rhuax lava stream + lithos stone
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Not Applicable
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Aphanitic, Glassy, Porphyritic
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Grey, White, Light Black
Durability
Durable
Durable
Appearance
Veined or Pebbled
Banded
Interior Uses
Not Yet Used
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
Not Yet Used
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Not Yet Used
Not Yet Used
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Gemstone, Laboratory bench tops, Jewelry
Types
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Features
Helps in production of Heat and Electricity, Used as fossil fuel
Acidic in nature, Available in lots of colors
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Not Yet Used
Formation
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.
Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.
Mineral Content
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
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Large and Coarse Grained
Fracture
Conchoidal
Sub-conchoidal
Porosity
Less Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Earthy
Compressive Strength
Not Available
Cleavage
Non-Existent
Not Available
Toughness
Not Available
2
Specific Gravity
1.1-1.4
2.65-2.67
Transparency
Opaque
Opaque
Density
1100-1400 g/cm3
2.4-2.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
China, India
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Germany, Iceland, Ireland, Italy, Spain
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Brazil, Chile, Colombia, Venezuela
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New Zealand, Queensland, Western Australia