Definition
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Origin
Webster, North Carolina
Egypt
Discoverer
Unknown
Unknown
Etymology
From the town of Webster located in North Carolina
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Class
Igneous Rocks
Igneous 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
Porphyritic
Color
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Black, Brown, Green, Grey, Red, Rust, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Dull
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Construction Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Creating Artwork, Gemstone, Jewelry
Types
Ultramafic rock
Rhomb Porphyry
Features
Generally rough to touch, Is one of the oldest rock
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Archaeological Significance
Formation
Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.
Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.
Mineral Content
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
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, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Coarse Grained
Fine Grained
Fracture
Uneven
Irregular
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Less Porous
Luster
Dull to Vitreous to Submetallic
Dull
Specific Gravity
3.2-3.5
2.5-4
Transparency
Opaque
Translucent to Opaque
Density
3.1-3.6 g/cm3
2.5-2.52 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Africa
South Africa
Egypt, Ethiopia, Ghana, South Africa
Europe
Germany, Greece, Italy, Scotland, Turkey
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, Cuba, Jamaica, USA
South America
Brazil, Colombia, Venezuela
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New South Wales, New Zealand, Western Australia
All about Websterite and Porphyry Properties
Know all about Websterite and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Websterite and Porphyry belong to Igneous Rocks.Texture of Websterite is Clastic, Granular, Phaneritic, Porphyritic whereas that of Porphyry is Porphyritic. Websterite appears Layered, Banded, Veined and Shiny and Porphyry appears Dull. The luster of Websterite is dull to vitreous to submetallic while that of Porphyry is dull. Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors whereas Porphyry is available in black, brown, green, grey, red, rust, white colors. The commercial uses of Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones and that of Porphyry are creating artwork, gemstone, jewelry.