Picrite

Websterite

Picrite and Websterite

Picrite

Websterite

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Definition

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.

History

Origin

Hawaii Islands

Webster, North Carolina

Discoverer

Unknown

Etymology

From Greek pikros bitter + -ite, 19th century

From the town of Webster located in North Carolina

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Earthy, Rough

Clastic, Granular, Phaneritic, Porphyritic

Color

Black, Brown, Green, Grey, Pink, White, Yellow

Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Shiny

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Homes, Interior Decoration

Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts

Other Uses

Commercial Uses

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones

Types

Oceanite

Ultramafic rock

Features

Host Rock for Lead

Generally rough to touch, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.

Composition

Mineral Content

Biotite, Olivine, Plagioclase, Pyrrhotite

Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene

Compound Content

Al, CaO, Carbon Dioxide, Mg, MgO

Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6.87

1 7

👆🏻

Grain Size

Fine Grained

Coarse Grained

Fracture

Uneven

Streak

White, Greenish White or Grey

Porosity

Less Porous

Luster

Subvitreous to Dull

Dull to Vitreous to Submetallic

Compressive Strength

189.00 N/mm²95.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

Specific Gravity

2.75-2.923.2-3.5

0 8.4

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Transparency

Opaque

Density

1.5-2.5 g/cm³3.1-3.6 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.88 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Africa

South Africa

Europe

Iceland

Germany, Greece, Italy, Scotland, Turkey

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

South America

Brazil

Brazil, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Queensland

All about Picrite and Websterite Properties

Know all about Picrite and Websterite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite and Websterite belong to Igneous Rocks.Texture of Picrite is Earthy, Rough whereas that of Websterite is Clastic, Granular, Phaneritic, Porphyritic. Picrite appears Rough and Shiny and Websterite appears Layered, Banded, Veined and Shiny. The luster of Picrite is subvitreous to dull while that of Websterite is dull to vitreous to submetallic. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.