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
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
Origin
European Foreland Basins
Germany
Discoverer
Unknown
Christian Leopold von Buch
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From Greek di + base
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic
Aphanitic, Granular
Color
Beige, Buff, Orange
Dark Grey to Black
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Vesicular
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Sedimentary rock
Dolerite
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Smooth to touch
Archaeological Significance
Famous Monuments
-
Stonehenge in English county of Wiltshire
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.
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
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
Fine to Medium Grained
Fracture
Irregular
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
-
Specific Gravity
1.10-2.24
2.86-2.87
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.7-3.3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
-
South Africa, Tanzania
Europe
United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Others
-
Antarctica, Greenland
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Argentina, Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
-
Central Australia, New Zealand, Queensland, Western Australia