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