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
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
Origin
European Foreland Basins
New Zealand
Discoverer
Unknown
Unknown
Etymology
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
From German which means hornstone
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic
Granular, Platy
Color
Beige, Buff, Orange
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Non-Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Dull
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Sedimentary rock
Biotite hornfels
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock
Smooth to touch
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. Hornfels 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
Andalusite
Compound Content
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
Fe, Mg
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Shiny
Specific Gravity
1.10-2.24
3.4-3.9
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
-
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
-
Cameroon, East Africa, Tanzania, Western Africa
Europe
United Kingdom
United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand, Queensland, Western Australia
Coquina vs Hornfels 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 Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Coquina and Properties of Hornfels. Learn more about Coquina vs Hornfels in the next section. The interior uses of Coquina include Decorative aggregates, Homes, Hotels and Interior decoration whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Coquina and Hornfels, they have various applications in construction industry. The uses of Coquina in construction industry include Building houses or walls, Construction aggregate and that of Hornfels include For road aggregate, Roadstone.
More about Coquina and Hornfels
Here you can know more about Coquina and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Coquina and Hornfels 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 Hornfels includes Andalusite. You can also check out the list of all Sedimentary Rocks. When we have to compare Coquina vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Coquina is available in beige, buff, orange colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Coquina is Layered, Banded, Veined and Shiny and that of Hornfels is Dull. Properties of rock is another aspect for Coquina vs Hornfels. The hardness of Coquina is 1-2 and that of Hornfels is 2-3. The types of Coquina are Sedimentary rock whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Coquina is white while that of Hornfels is . The specific heat capacity of Coquina is 0.84 kJ/Kg K and that of Hornfels is 0.84 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 Hornfels is heat resistant, impact resistant, pressure resistant.