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
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
Origin
European Foreland Basins
France
Discoverer
Unknown
Alexandre Brongniart
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Not Applicable
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Color
Beige, Buff, Orange
Reddish Brown
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Rough and Dull
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
Construction Industry
Building houses or walls, Construction Aggregate
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork
In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
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.
Arkose rock forms from the weathering of feldspar-rich igneous or metamorphic rock, most commonly granitic rocks, which are primarily composed of quartz and feldspar.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Not Applicable
Not Applicable
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
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Coarse Grained
Fracture
Irregular
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Dull
Cleavage
Not Available
Not Available
Toughness
Not Available
Not Available
Specific Gravity
1.10-2.24
0
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Not Yet Found
Namibia, Nigeria, South Africa
Europe
United Kingdom
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
USA
Canada, USA
South America
Not Yet Found
Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, New Zealand