Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Aphanitic
Porphyritic
Color
Black, Brown, Green, Grey, White
Blue, Bluish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Foliated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers
Types
Peralkaline Nephelinite
Rhyolite
Features
Host Rock for Lead
Very fine grained rock, It is One of the Oldest, Strongest and Hardest 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.
Comendite is a type of Igneous rock which is formed due to cooling and solidification of lava or magma. It may form with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Albite, Amphibole, Quartz
Compound Content
Ca, CaO, Carbon, Cl, MgO
Al, Fe, Potassium Oxide
Types of Metamorphism
Contact Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Medium Grained
Streak
White
Bluish Black
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
Dull
Specific Gravity
2.4-2.9
2.38
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
-9999 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
East Africa
Deposits in Western Continents
North America
Canada, USA
-
Deposits in Oceania Continent
All about Nephelinite and Comendite Properties
Know all about Nephelinite and Comendite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Comendite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Comendite is Porphyritic. Nephelinite appears Skeletal and Comendite appears Foliated. The luster of Nephelinite is vitreous to metallic while that of Comendite is dull. Nephelinite is available in black, brown, green, grey, white colors whereas Comendite is available in blue, bluish - grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Comendite are cemetery markers.