Definition
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Origin
Webster, North Carolina
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Discoverer
Unknown
Unknown
Etymology
From the town of Webster located in North Carolina
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
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic, Granular, Phaneritic, Porphyritic
Banded, Rough
Color
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Glassy or Pearly
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, 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 Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Ultramafic rock
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Generally rough to touch, Is one of the oldest rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Formation
Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.
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
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
Quartz, Silicon
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
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Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
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Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Coarse Grained
Very fine-grained
Fracture
Uneven
Uneven, Splintery or Conchoidal
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Waxy and Dull
Specific Gravity
3.2-3.5
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
3.1-3.6 g/cm3
2.7 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear 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
Germany, Greece, Italy, Scotland, Turkey
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Greenland
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil, Colombia, Venezuela
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New South Wales, Queensland, South Australia, Western Australia
Websterite 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. Websterite vs Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Websterite and Properties of Chert. Learn more about Websterite vs Chert in the next section. The interior uses of Websterite include Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring and Interior decoration whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Websterite and Chert, they have various applications in construction industry. The uses of Websterite in construction industry include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate and that of Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Websterite and Chert
Here you can know more about Websterite and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Websterite and Chert consists of mineral content and compound content. The mineral content of Websterite includes Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Igneous Rocks. When we have to compare Websterite vs Chert, the texture, color and appearance plays an important role in determining the type of rock. Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors whereas, Chert is available in black, brown, green, grey, red, white colors. Appearance of Websterite is Layered, Banded, Veined and Shiny and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Websterite vs Chert. The hardness of Websterite is 7 and that of Chert is 6.5-7. The types of Websterite are Ultramafic rock 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 Websterite and Chert is white, greenish white or grey. The specific heat capacity of Websterite is 0.79 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.Websterite is impact resistant, pressure resistant, wear resistant whereas Chert is heat resistant, impact resistant, pressure resistant, wear resistant.