1 Definition
1.1 Definition
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
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
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
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
Fine Grained Rock, Opaque Rock
Opaque Rock
2 Texture
2.1 Texture
2.2 Color
Brown, Buff, Cream, Green, Grey, Pink, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
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
Banded and Foilated
Shiny
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
3.2.2 Medical Industry
3.3 Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Jewellery
3.4 Other Uses
3.4.1 Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Mirror, Used in aquariums
4 Types
4.1 Types
Borolanite and Litchfieldite
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
4.2 Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock
Blocks negativity, Helps to protect against depression
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Data Not Available
Not Applicable
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Not Applicable
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 Formation
Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
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.
5.2 Composition
5.2.1 Mineral Content
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
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
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Fine Grained
Not Applicable
6.1.3 Fracture
Conchoidal to Uneven
Conchoidal
6.1.4 Streak
6.1.5 Porosity
Less Porous
Very Less Porous
6.1.6 Luster
6.1.7 Compressive Strength
150.00 N/mm20.15 N/mm2
0.15
450
6.1.8 Cleavage
6.1.9 Toughness
Not Available
Not Available
6.1.10 Specific Gravity
6.1.11 Transparency
Translucent to Opaque
Translucent
6.1.12 Density
2.6 g/cm32.6 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
6.2.2 Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Afghanistan, Indonesia, Japan, Russia
7.1.2 Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Kenya
7.1.3 Europe
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Greece, Hungary, Iceland, Italy, Turkey
7.1.4 Others
7.2 Deposits in Western Continents
7.2.1 North America
Canada, USA
Canada, Mexico, USA
7.2.2 South America
Brazil, Chile, Colombia, Uruguay, Venezuela
Argentina, Chile, Ecuador, Peru
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
New Zealand