Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
  
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
  
History
  
  
Origin
Hawaii Islands
  
European Foreland Basins
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Greek pikros bitter + -ite, 19th century
  
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
  
Class
Igneous Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Opaque Rock
  
Texture
Earthy, Rough
  
Clastic
  
Color
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
  
Beige, Buff, Orange
  
Maintenance
Less
  
More
  
Durability
Durable
  
Non-Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
Yes
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Rough and Shiny
  
Layered, Banded, Veined and Shiny
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Homes, Hotels, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
  
Building houses or walls, Construction Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
  
Creating Artwork
  
Types
Oceanite
  
Not Available
  
Features
Host Rock for Lead
  
Available in Lots of Colors and Patterns, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Present
  
Formation
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
  
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.
  
Composition
  
  
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
  
Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite
  
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
  
CaO, Carbon Dioxide, Iron(III) Oxide, MgO
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
6.8
  
1-2
  
Grain Size
Fine Grained
  
Coarse Grained
  
Fracture
Uneven
  
Irregular
  
Streak
White, Greenish White or Grey
  
White
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Subvitreous to Dull
  
Dull to Vitreous to Submetallic
  
Compressive Strength
189.00 N/mm
2
  
11
Not Available
  
Cleavage
Imperfect
  
Not Available
  
Toughness
2.1
  
Not Available
  
Specific Gravity
2.75-2.92
  
1.10-2.24
  
Transparency
Opaque
  
Opaque
  
Density
1.5-2.5 g/cm3
  
2.8-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.88 kJ/Kg K
  
13
Not Available
  
Resistance
Heat Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Not Yet Found
  
Africa
South Africa
  
Not Yet Found
  
Europe
Iceland
  
United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Brazil
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
Not Yet Found
  
Picrite vs Coquina 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. Picrite vs Coquina characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Picrite and Properties of Coquina. Learn more about Picrite vs Coquina in the next section. The interior uses of Picrite include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Coquina include Decorative aggregates, Homes, Hotels and Interior decoration. Due to some exceptional properties of Picrite and Coquina, they have various applications in construction industry. The uses of Picrite in construction industry include As a sintering agent in steel industry to process iron ore, Cement manufacture, For road aggregate, Manufacture of magnesium and dolomite refractories, Roadstone, Used for flooring, stair treads, borders and window sills. and that of Coquina include Building houses or walls, Construction aggregate.
More about Picrite and Coquina
Here you can know more about Picrite and Coquina. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Picrite and Coquina consists of mineral content and compound content. The mineral content of Picrite includes Biotite, Olivine, Plagioclase, Pyrrhotite and mineral content of Coquina includes Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite. You can also check out the list of all Igneous Rocks. When we have to compare Picrite vs Coquina, the texture, color and appearance plays an important role in determining the type of rock. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas, Coquina is available in beige, buff, orange colors. Appearance of Picrite is Rough and Shiny and that of Coquina is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Picrite vs Coquina. The hardness of Picrite is 6.8 and that of Coquina is 1-2. The types of Picrite are Oceanite whereas types of Coquina are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Picrite and Coquina is white, greenish white or grey. The specific heat capacity of Picrite is 0.88 kJ/Kg K and that of Coquina is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Picrite is heat resistant whereas Coquina is heat resistant, impact resistant, pressure resistant, wear resistant.