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
Mudstone is a fine-grained, dark gray sedimentary rock, which is formed from silt and clay and is similar to shale but has less laminations
Origin
European Foreland Basins
-
Discoverer
Unknown
William Smith
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From the English mud and stone, from low German mudde and stainaz
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Beige, Buff, Orange
Black, Blue, Brown, Green, Grey, Orange, Red, White, Yellow
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Rough and Dull
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Decorative Aggregates, Entryways, Floor Tiles, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Sculpture, Small Figurines
Commercial Uses
Creating Artwork
Creating Artwork, Pottery
Types
Sedimentary rock
Marl, Shale and Argillite
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Available in Lots of Colors and Patterns, Smooth to touch, Very fine grained rock
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.
Mudstone forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are buried and compacted by overlying sediment hence forming mudstone.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion
Grain Size
Coarse Grained
Very fine-grained
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Dull
Specific Gravity
1.10-2.24
2.2-2.8
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.4-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
-
Bangladesh, China, India, Russia
Africa
-
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
South America
-
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand, Queensland, Victoria, Western Australia