Websterite and Chert
Definition
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
History
Origin
Webster, North Carolina
Unknown
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
Family
Group
Plutonic
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
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
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
Yes
Yes
Wind Resistant
Yes
No
Acid Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Glassy or Pearly
Uses
Architecture
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
Industry
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments
Other Uses
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
Types
Not Available
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
Monuments
Not Yet Used
Used
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Not Yet Used
Fossils
Absent
Present
Formation
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.
Composition
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
Transformation
Metamorphism
Yes
No
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Not Applicable
Weathering
Yes
No
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Properties
Physical Properties
Hardness
7
6.5-7
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
Compressive Strength
Not Available
450.00 N/mm2
1
Cleavage
Irregular
Non-Existent
Toughness
Not Available
1.5
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
Thermal Properties
Specific Heat Capacity
Not Available
0.74 kJ/Kg K
19
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Reserves
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
All about Websterite and Chert Properties
Know all about Websterite and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Websterite belongs to Igneous Rocks while Chert belongs to Sedimentary Rocks.Texture of Websterite is Clastic, Granular, Phaneritic, Porphyritic whereas that of Chert is Banded, Rough. Websterite appears Layered, Banded, Veined and Shiny and Chert appears Glassy or Pearly. The luster of Websterite is dull to vitreous to submetallic while that of Chert is waxy and dull. 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. The commercial uses of Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones and that of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.
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