1 Definition
1.1 Definition
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From French, Latin lignum wood + -ite1
1.4 Class
Igneous Rocks
Sedimentary Rocks
1.4.1 Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
2.2 Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black, Brown, Dark Brown, Grey, Light to Dark Grey
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Interior Decoration
Not Yet Used
3.1.2 Exterior Uses
Garden Decoration
Not Yet Used
3.1.3 Other Architectural Uses
Not Yet Used
Not Yet Used
3.2 Industry
3.2.1 Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
for Road Aggregate, Steel Production
3.2.2 Medical Industry
3.3 Antiquity Uses
Artifacts, Jewellery
Not Yet Used
3.4 Other Uses
3.4.1 Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Electricity Generation
4 Types
4.1 Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
4.2 Features
Blocks negativity, Helps to protect against depression
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
4.3 Archaeological Significance
4.3.1 Monuments
Not Yet Used
Not Yet Used
4.3.2 Famous Monuments
Not Applicable
Not Applicable
4.3.3 Sculpture
Not Yet Used
Not Yet Used
4.3.4 Famous Sculptures
Not Applicable
Not Applicable
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
Not Yet Used
Not Yet Used
4.4 Fossils
5 Formation
5.1 Formation
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
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.
5.2 Composition
5.2.1 Mineral Content
Not Available
Not Available
5.2.2 Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Not Applicable
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Water Erosion, Wind Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Not Applicable
Medium to Fine Coarse Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Very Less Porous
Highly Porous
6.1.6 Luster
Vitreous
Dull to Vitreous to Submetallic
6.1.7 Compressive Strength
6.1.8 Cleavage
Non-Existent
Non-Existent
6.1.9 Toughness
Not Available
Not Available
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
2.6 g/cm3800-801 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K1.26 kJ/Kg K
0.14
3.2
6.2.2 Resistance
Heat Resistant, Impact Resistant
Heat Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Afghanistan, Indonesia, Japan, Russia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
7.1.2 Africa
Kenya
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
7.1.3 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
7.1.4 Others
Not Yet Found
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
Canada, Mexico, USA
Canada, Mexico, USA
7.2.2 South America
Argentina, Chile, Ecuador, Peru
Brazil, Chile, Colombia, Venezuela
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand
New South Wales, Queensland, Victoria