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
Talc carbonate is nothing but a rock sequence or a mineral composition found in metamorphic ultramafic rocks.
History
Origin
Ethiopia
China, USA, Middle east
Discoverer
Obsius
Unknown
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From medieval Latin, talcum
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Family
Group
Volcanic
-
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy
Very Soft
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Shiny
Soft
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration
Garden Decoration
Other Architectural Uses
-
Powder
Industry
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Source of calcium
Medical Industry
Surgery
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Jewellery
Artifacts, Jewellery, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Manufacturing of baby powder
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Sedimentary rock
Features
Blocks negativity, Helps to protect against depression
Easily splits into thin plates, Generally rough to touch, Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Talc Carbonate is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Composition
Mineral Content
-
Carbonate, Chlorite, Magnesium
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
CaO, Carbon Dioxide, MgO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
-
Physical Properties
Hardness
5-5.51-2
1
7
👆🏻
Grain Size
-
Fine Grained
Fracture
Conchoidal
Flat
Streak
White
White
Porosity
Very Less Porous
Less Porous
Luster
Vitreous
Pearly
Compressive Strength
0.15 N/mm2250.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
-
1
Specific Gravity
2.6-2.72.86
0
8.4
👆🏻
Transparency
Translucent
Translucent
Density
2.6 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
-
Africa
Kenya
Ethiopia, Ghana, Western Africa
Europe
Greece, Hungary, Iceland, Italy, Turkey
England
Others
-
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Argentina, Chile, Ecuador, Peru
Argentina, Bolivia, Uruguay
Deposits in Oceania Continent
Australia
New Zealand
Central Australia, South Australia, Western Australia