Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
  
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
  
History
  
  
Origin
Brazil
  
Romania and Moldova, Europe
  
Discoverer
Unknown
  
Unknown
  
Etymology
from French néphéline, from Greek nephelē
  
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Aphanitic
  
Aphanitic to Porphyritic
  
Color
Black, Brown, Colourless, Green, Grey, White
  
Bluish - Grey, Brown, Grey, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
Yes
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Skeletal
  
Vesicular
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Entryways, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
As Building Stone, Paving Stone, Garden Decoration
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
  
Commemorative Tablets, Creating Artwork
  
Types
Peralkaline Nephelinite
  
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
  
Features
Host Rock for Lead
  
Host Rock for Lead, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
Nephelinite 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.
  
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
  
Composition
  
  
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
  
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
  
Compound Content
Ca, CaO, Carbon, Cl, MgO
  
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
  
Chemical Erosion
  
Physical Properties
  
  
Hardness
6.5
  
2-2.25
  
Grain Size
Fine Grained
  
Medium to Fine Coarse Grained
  
Fracture
Flat
  
Conchoidal
  
Streak
White
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Vitreous to Metallic
  
Subvitreous to Dull
  
Compressive Strength
35.00 N/mm
2
  
29
Not Available
  
Cleavage
Imperfect
  
Perfect
  
Toughness
2.7
  
Not Available
  
Specific Gravity
2.4-2.9
  
2.86-2.87
  
Transparency
Opaque
  
Translucent
  
Density
2.5-3 g/cm3
  
2.77-2.771 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.88 kJ/Kg K
  
13
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Japan
  
Not Yet Found
  
Africa
Rwanda, Tanzania
  
Not Yet Found
  
Europe
Not Yet Found
  
France, Greece, Romania, Scotland, Spain
  
Others
Hawaii Islands
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Colombia
  
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New Zealand, South Australia, Western Australia
  
Nephelinite vs Dacite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Nephelinite vs Dacite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Nephelinite and Properties of Dacite. Learn more about Nephelinite vs Dacite in the next section. The interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Dacite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Nephelinite and Dacite, they have various applications in construction industry. The uses of Nephelinite in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate and that of Dacite include As dimension stone, Construction aggregate, For road aggregate, Landscaping.
More about Nephelinite and Dacite
Here you can know more about Nephelinite and Dacite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Nephelinite and Dacite consists of mineral content and compound content. The mineral content of Nephelinite includes Clinopyroxene, Nepheline, Plagioclase and mineral content of Dacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Nephelinite vs Dacite, the texture, color and appearance plays an important role in determining the type of rock. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas, Dacite is available in bluish - grey, brown, grey, light to dark grey colors. Appearance of Nephelinite is Skeletal and that of Dacite is Vesicular. Properties of rock is another aspect for Nephelinite vs Dacite. The hardness of Nephelinite is 6.5 and that of Dacite is 2-2.25. The types of Nephelinite are Peralkaline Nephelinite whereas types of Dacite are Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Nephelinite and Dacite is white. The specific heat capacity of Nephelinite is 0.88 kJ/Kg K and that of Dacite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Nephelinite is heat resistant whereas Dacite is heat resistant, impact resistant, pressure resistant, wear resistant.