Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
History
Origin
France
-
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
From English feldspar and -ite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Arborescent Patterned, Vitreous
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Veined or Pebbled
Layered, Banded, Veined and Shiny
Architecture
Interior Uses
-
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
-
Paving Stone, Garden Decoration
Other Architectural Uses
-
Curbing
Industry
Construction Industry
for Road Aggregate, Steel Production
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
-
Artifacts
Other Uses
Commercial Uses
Electricity Generation
Mirror, Jewelry
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Igneous rock
Features
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
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.
Felsite 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.
Composition
Mineral Content
-
Feldspar, Iron Oxides
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Water Erosion
Physical Properties
Hardness
15-5.5
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
Black
White
Porosity
Highly Porous
Very Less Porous
Luster
Dull to Vitreous to Submetallic
Vitreous
Compressive Strength
-0.15 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
-
Specific Gravity
1.1-1.42.6-2.7
0
8.4
👆🏻
Transparency
Opaque
Translucent
Density
800-801 g/cm32.6 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.26 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Afghanistan, Indonesia, Japan, Russia
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Kenya
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
-
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Mexico, USA
South America
Brazil, Chile, Colombia, Venezuela
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New Zealand