Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Coquina is a sedimentary rock that is composed either wholly or almost entirely of the transported, abraded, and mechanically-sorted fragments of the shells of molluscs, trilobites, brachiopods, or other invertebrates
Origin
Brazil
European Foreland Basins
Discoverer
Unknown
Unknown
Etymology
from French néphéline, from Greek nephelē
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Aphanitic
Clastic
Color
Black, Brown, Colourless, Green, Grey, White
Beige, Buff, Orange
Durability
Durable
Non-Durable
Appearance
Skeletal
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Hotels, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Building houses or walls, Construction Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Creating Artwork
Types
Peralkaline Nephelinite
Not Available
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
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.
Coquina is a sedimentary rock which is formed when billions of small clam-like seashell, called Coquina, or cockleshell are die and hence are deposited, buried and turns into a rock when pressure is applied.
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Compound Content
Ca, CaO, Carbon, Cl, MgO
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Types of Metamorphism
Contact Metamorphism
Not Applicable
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, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Coarse Grained
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
Dull to Vitreous to Submetallic
Compressive Strength
Not Available
Cleavage
Imperfect
Not Available
Toughness
2.7
Not Available
Specific Gravity
2.4-2.9
1.10-2.24
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
2.8-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
Not Yet Found
Europe
Not Yet Found
United Kingdom
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Not Yet Found
All about Nephelinite and Coquina Properties
Know all about Nephelinite and Coquina properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Coquina belongs to Sedimentary Rocks.Texture of Nephelinite is Aphanitic whereas that of Coquina is Clastic. Nephelinite appears Skeletal and Coquina appears Layered, Banded, Veined and Shiny. The luster of Nephelinite is vitreous to metallic while that of Coquina is dull to vitreous to submetallic. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Coquina is available in beige, buff, orange colors. The commercial uses of Nephelinite and Coquina are creating artwork, soil conditioner, source of magnesia (mgo).