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
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
1.4 Class
Igneous Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
2 Texture
2.1 Texture
2.2 Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black to Grey, Dark Greenish - 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
Decorative Aggregates, Interior Decoration
3.1.2 Exterior Uses
Garden Decoration
As Building Stone, Garden Decoration
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
3.2.2 Medical Industry
3.3 Antiquity Uses
Artifacts, Jewellery
Artifacts
3.4 Other Uses
3.4.1 Commercial Uses
Creating Artwork, Mirror, Used in aquariums
Cemetery Markers, Creating Artwork
4 Types
4.1 Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Not Available
4.2 Features
Blocks negativity, Helps to protect against depression
Available in Lots of Colors and Patterns
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.
Rhyodacite 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.
5.2 Composition
5.2.1 Mineral Content
Not Available
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
5.2.2 Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, Fe, Potassium Oxide, NA, Potassium, Silicon Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
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, Coastal Erosion, Glacier Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Not Applicable
Fine Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Very Less Porous
Less Porous
6.1.6 Luster
6.1.7 Compressive Strength
0.15 N/mm2200.50 N/mm2
0.15
450
6.1.8 Cleavage
Non-Existent
Not Available
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
2.6 g/cm3Not Available
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K1.12 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
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
7.1.2 Africa
Kenya
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
7.1.3 Europe
Greece, Hungary, Iceland, Italy, Turkey
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland
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, USA
7.2.2 South America
Argentina, Chile, Ecuador, Peru
Not Yet Found
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand
Not Yet Found