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
A hydration and metamorphic transformation of ultramafic rock from the Earth's mantle is called as serpentinization, a group of minerals is formed by serpentinization compose rock 'serpentinite'.
Origin
European Foreland Basins
USA
Discoverer
Unknown
Unknown
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From English word serpentinization.
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Beige, Buff, Orange
Black, Brown, Green, Grey, White
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Rough and Dull
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Creating Artwork
Commemorative Tablets, Creating Artwork
Types
Sedimentary rock
Jadeitite
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Serpentinite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Carbonate, Magnetite, Pyrrhotite, Serpentine, Sulfides
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Ca, CaO, Carbon Dioxide, KCl, MgO, Sulfur Dioxide, Sulphur
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Grain Size
Coarse Grained
Very fine-grained
Fracture
Irregular
Uneven
Streak
White
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
Waxy and Dull
Specific Gravity
1.10-2.24
2.79-3
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
-
India, Saudi Arabia, Singapore, South Korea
Africa
-
Ethiopia, Western Africa
Europe
United Kingdom
England, Georgia, Switzerland, United Kingdom
Deposits in Western Continents
Deposits in Oceania Continent
Australia
-
Central Australia, New South Wales, New Zealand, Western Australia