Definition
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
  
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
  
History
  
  
Origin
Webster, North Carolina
  
France
  
Discoverer
Unknown
  
Alexandre Brongniart
  
Etymology
From the town of Webster located in North Carolina
  
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
  
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
  
Coarse Grained Rock, Opaque Rock
  
Texture
Clastic, Granular, Phaneritic, Porphyritic
  
Clastic
  
Color
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
  
Reddish Brown
  
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
  
Rough and Dull
  
Architecture
  
  
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
  
Paving Stone, Office Buildings
  
Other Architectural Uses
Curbing
  
Whetstones
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
  
In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones
  
Types
Not Available
  
Not Available
  
Features
Generally rough to touch, Is one of the oldest rock
  
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Present
  
Formation
Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.
  
Arkose rock forms from the weathering of feldspar-rich igneous or metamorphic rock, most commonly granitic rocks, which are primarily composed of quartz and feldspar.
  
Composition
  
  
Mineral Content
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
  
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
  
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
7
  
6-7
  
Grain Size
Coarse Grained
  
Coarse Grained
  
Fracture
Uneven
  
Conchoidal
  
Streak
White, Greenish White or Grey
  
White
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Dull to Vitreous to Submetallic
  
Dull
  
Cleavage
Irregular
  
Not Available
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
3.2-3.5
  
0
  
Transparency
Opaque
  
Opaque
  
Density
3.1-3.6 g/cm3
  
Not Available
  
Thermal Properties
  
  
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
Africa
South Africa
  
Namibia, Nigeria, South Africa
  
Europe
Germany, Greece, Italy, Scotland, Turkey
  
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
Others
Greenland
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil, Colombia, Venezuela
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Queensland
  
New South Wales, New Zealand