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
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
Origin
European Foreland Basins
Ethiopia
Discoverer
Unknown
Obsius
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Opaque Rock
Color
Beige, Buff, Orange
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Shiny
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
Garden Decoration
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Building houses or walls, Construction Aggregate
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
Not Yet Used
Surgery
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery
Commercial Uses
Creating Artwork
Creating Artwork, Mirror, Used in aquariums
Types
Not Available
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Blocks negativity, Helps to protect against depression
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
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.
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
Mineral Content
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
Not Available
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Coarse Grained
Not Applicable
Fracture
Irregular
Conchoidal
Porosity
Highly Porous
Very Less Porous
Luster
Dull to Vitreous to Submetallic
Vitreous
Compressive Strength
Not Available
Cleavage
Not Available
Non-Existent
Toughness
Not Available
Not Available
Specific Gravity
1.10-2.24
2.6-2.7
Transparency
Opaque
Translucent
Density
2.8-2.9 g/cm3
2.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
Afghanistan, Indonesia, Japan, Russia
Africa
Not Yet Found
Kenya
Europe
United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
Not Yet Found
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand
Coquina vs Obsidian 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 Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Coquina and Properties of Obsidian. Learn more about Coquina vs Obsidian in the next section. The interior uses of Coquina include Decorative aggregates, Homes, Hotels and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Coquina and Obsidian, they have various applications in construction industry. The uses of Coquina in construction industry include Building houses or walls, Construction aggregate and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Coquina and Obsidian
Here you can know more about Coquina and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Coquina and Obsidian 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 Obsidian is not available. You can also check out the list of all Sedimentary Rocks. When we have to compare Coquina vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Coquina is available in beige, buff, orange colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Coquina is Layered, Banded, Veined and Shiny and that of Obsidian is Shiny. Properties of rock is another aspect for Coquina vs Obsidian. The hardness of Coquina is 1-2 and that of Obsidian is 5-5.5. The types of Coquina are Not Available whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Coquina and Obsidian is white. The specific heat capacity of Coquina is Not Available and that of Obsidian is 0.92 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 Obsidian is heat resistant, impact resistant.
