Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From French, Latin lignum wood + -ite1
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard 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
Aphanitic to Porphyritic
Amorphous, Glassy
Color
Black, Brown, Green, Grey, White
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Vesicular
Veined or Pebbled
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
-
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
-
Other Architectural Uses
Curbing
-
Construction Industry
Landscaping
for Road Aggregate, Steel Production
Antiquity Uses
Artifacts, Sculpture
-
Commercial Uses
Production of Lime, Soil Conditioner
Electricity Generation
Types
Igneous rock
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Features
Host Rock for Lead
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Formation
Tephrite 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 formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
-
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
Cataclastic Metamorphism, Contact 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, Sea Erosion, Water Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
Black
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull to Vitreous to Submetallic
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.86
1.1-1.4
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
800-801 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
-
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
Namibia, Uganda
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
Germany, Hungary, Italy, Portugal, Spain
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
New Zealand, Western Australia
New South Wales, Queensland, Victoria