Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Origin
Hawaii Islands
Unknown
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Banded, Rough
Color
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Glassy or Pearly
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
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.
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Oceanite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Host Rock for Lead
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Not Yet Used
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.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Quartz, Silicon
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering
Not Applicable
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Uneven
Uneven, Splintery or Conchoidal
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Waxy and Dull
Cleavage
Imperfect
Non-Existent
Specific Gravity
2.75-2.92
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
1.5-2.5 g/cm3
2.7 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Iceland
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, Queensland, South Australia, Western Australia
Picrite vs Chert 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 Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Picrite and Properties of Chert. Learn more about Picrite vs Chert in the next section. The interior uses of Picrite include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Picrite and Chert, 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 Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Picrite and Chert
Here you can know more about Picrite and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Picrite and Chert consists of mineral content and compound content. The mineral content of Picrite includes Biotite, Olivine, Plagioclase, Pyrrhotite and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Igneous Rocks. When we have to compare Picrite vs Chert, 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, Chert is available in black, brown, green, grey, red, white colors. Appearance of Picrite is Rough and Shiny and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Picrite vs Chert. The hardness of Picrite is 6.8 and that of Chert is 6.5-7. The types of Picrite are Oceanite whereas types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Picrite and Chert is white, greenish white or grey. The specific heat capacity of Picrite is 0.88 kJ/Kg K and that of Chert is 0.74 kJ/Kg K. 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 Chert is heat resistant, impact resistant, pressure resistant, wear resistant.
