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
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Origin
European Foreland Basins
Unknown
Discoverer
Unknown
Unknown
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
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
Fine Grained Rock, Opaque Rock
Texture
Clastic
Banded, Rough
Color
Beige, Buff, Orange
Black, Brown, Green, Grey, Red, White
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Glassy or Pearly
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Creating Artwork
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Not Available
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Not Yet 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.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Quartz, Silicon
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Silicon Dioxide
Types of Metamorphism
Not Applicable
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Coarse Grained
Very fine-grained
Fracture
Irregular
Uneven, Splintery or Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Waxy and Dull
Compressive Strength
Not Available
Cleavage
Not Available
Non-Existent
Toughness
Not Available
1.5
Specific Gravity
1.10-2.24
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
2.8-2.9 g/cm3
2.7 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Not Yet Found
Kenya, Morocco, South Africa, Tanzania
Europe
United Kingdom
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
Not Yet Found
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, Queensland, South Australia, Western Australia
Coquina vs Chert Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Coquina vs Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Coquina and Properties of Chert. Learn more about Coquina vs Chert in the next section. The interior uses of Coquina include Decorative aggregates, Homes, Hotels and Interior decoration whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Coquina and Chert, they have various applications in construction industry. The uses of Coquina in construction industry include Building houses or walls, Construction aggregate and that of Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Coquina and Chert
Here you can know more about Coquina and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Coquina and Chert consists of mineral content and compound content. The mineral content of Coquina includes Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Sedimentary Rocks. When we have to compare Coquina vs Chert, the texture, color and appearance plays an important role in determining the type of rock. Coquina is available in beige, buff, orange colors whereas, Chert is available in black, brown, green, grey, red, white colors. Appearance of Coquina is Layered, Banded, Veined and Shiny and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Coquina vs Chert. The hardness of Coquina is 1-2 and that of Chert is 6.5-7. The types of Coquina are Not Available whereas types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Coquina and Chert is white. The specific heat capacity of Coquina is Not Available and that of Chert is 0.74 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Coquina is heat resistant, impact resistant, pressure resistant, wear resistant whereas Chert is heat resistant, impact resistant, pressure resistant, wear resistant.