Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
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 German Tachylite, from tachy- + Greek lutos soluble, melting
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
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Vitreous
Amorphous, Glassy
Color
Black, Dark Brown
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Glassy
Veined or Pebbled
Interior Uses
Decorative Aggregates, Interior Decoration
-
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
-
Other Architectural Uses
Curbing
-
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
Cemetery Markers, Creating Artwork
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Types
Volcanic glass
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Formation
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.
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
Feldspar, Olivine
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
Fe, Mg
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
-
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Less Porous
Luster
Resinous
Dull to Vitreous to Submetallic
Specific Gravity
2.4
1.1-1.4
Transparency
Opaque
Opaque
Density
3.058 g/cm3
1100-1400 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Cambodia, Russia, South Korea
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
East Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
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
USA
Canada, Mexico, USA
South America
-
Brazil, Chile, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Victoria
New South Wales, Queensland, Victoria