Definition
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate
Origin
Webster, North Carolina
Unknown
Discoverer
Unknown
Unknown
Etymology
From the town of Webster located in North Carolina
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Group
Plutonic
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic, Granular, Phaneritic, Porphyritic
Clastic, Polished
Color
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Dark Grey to Black, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Rough and Dull
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Used for flooring, stair treads, borders and window sills.
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Fire resistant, Used to manufracture paperweights and bookends
Types
Not Available
Not Available
Features
Generally rough to touch, Is one of the oldest rock
Is one of the oldest rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Used
Formation
Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.
An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.
Mineral Content
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Coarse Grained
Fine Grained
Fracture
Uneven
Conchoidal to Uneven
Streak
White, Greenish White or Grey
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Waxy and Dull
Toughness
Not Available
2.6
Specific Gravity
3.2-3.5
2.56-2.68
Transparency
Opaque
Opaque
Density
3.1-3.6 g/cm3
2.54-2.66 g/cm3
Specific Heat Capacity
Not Available
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Russia
Bangladesh, China, India, Russia
Africa
South Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Germany, Greece, Italy, Scotland, Turkey
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil, Colombia, Venezuela
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New South Wales, New Zealand, Queensland, Victoria, Western Australia
All about Websterite and Argillite Properties
Know all about Websterite and Argillite properties here. All properties of rocks are important as they define the type of rock and its application. Websterite belongs to Igneous Rocks while Argillite belongs to Sedimentary Rocks.Texture of Websterite is Clastic, Granular, Phaneritic, Porphyritic whereas that of Argillite is Clastic, Polished. Websterite appears Layered, Banded, Veined and Shiny and Argillite appears Rough and Dull. The luster of Websterite is dull to vitreous to submetallic while that of Argillite is waxy and dull. Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors whereas Argillite is available in dark grey to black, pink, 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 Argillite are fire resistant, used to manufracture paperweights and bookends.