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
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Origin
European Foreland Basins
Unknown
Discoverer
Unknown
Unknown
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Group
Not Applicable
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic
Clastic or Non-Clastic
Color
Beige, Buff, Orange
Grey, White, Yellow
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Soft
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, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Powder
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork
Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
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.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Ca, NaCl, CaO
Types of Metamorphism
Not Applicable
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Coarse Grained
Very fine-grained
Fracture
Irregular
Not Available
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Dull
Cleavage
Not Available
Non-Existent
Toughness
Not Available
1
Specific Gravity
1.10-2.24
2.3-2.4
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.49-2.50 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Not Yet Found
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
United Kingdom
England, France, Germany, Spain, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Not Yet Found
Colombia
Deposits in Oceania Continent
Australia
Not Yet Found
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula
Coquina vs Chalk 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 Chalk characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Coquina and Properties of Chalk. Learn more about Coquina vs Chalk in the next section. The interior uses of Coquina include Decorative aggregates, Homes, Hotels and Interior decoration whereas the interior uses of Chalk include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Coquina and Chalk, they have various applications in construction industry. The uses of Coquina in construction industry include Building houses or walls, Construction aggregate and that of Chalk include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for manufacture of quicklime and slaked lime, Source of calcium.
More about Coquina and Chalk
Here you can know more about Coquina and Chalk. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Coquina and Chalk 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 Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand. You can also check out the list of all Sedimentary Rocks. When we have to compare Coquina vs Chalk, the texture, color and appearance plays an important role in determining the type of rock. Coquina is available in beige, buff, orange colors whereas, Chalk is available in grey, white, yellow colors. Appearance of Coquina is Layered, Banded, Veined and Shiny and that of Chalk is Soft. Properties of rock is another aspect for Coquina vs Chalk. The hardness of Coquina is 1-2 and that of Chalk is 1. The types of Coquina are Not Available whereas types of Chalk are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Coquina and Chalk is white. The specific heat capacity of Coquina is Not Available and that of Chalk is 0.90 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 Chalk is heat resistant.