Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Clastic, Polished
Color
Black, Brown, Green, Grey, White
Dark Grey to Black, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Rough and Dull
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Used for flooring, stair treads, borders and window sills.
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Fire resistant, Used to manufracture paperweights and bookends
Types
Peralkaline Nephelinite
Metamorphic rock
Features
Host Rock for Lead
Is one of the oldest rock
Archaeological Significance
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.
An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Ca, CaO, Carbon, Cl, MgO
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Contact Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Flat
Conchoidal to Uneven
Streak
White
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
Waxy and Dull
Specific Gravity
2.4-2.9
2.56-2.68
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
2.54-2.66 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Japan
Bangladesh, China, India, Russia
Africa
Rwanda, Tanzania
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
-
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand, Queensland, Victoria, Western Australia
All about Nephelinite and Argillite Properties
Know all about Nephelinite and Argillite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Argillite belongs to Sedimentary Rocks.Texture of Nephelinite is Aphanitic whereas that of Argillite is Clastic, Polished. Nephelinite appears Skeletal and Argillite appears Rough and Dull. The luster of Nephelinite is vitreous to metallic while that of Argillite is waxy and dull. Nephelinite is available in black, brown, green, grey, white colors whereas Argillite is available in dark grey to black, pink, red, white colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Argillite are fire resistant, used to manufracture paperweights and bookends.