Nephelinite

Websterite

Nephelinite and Websterite

Nephelinite

Websterite

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Definition

Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).

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

Brazil

Webster, North Carolina

Discoverer

Unknown

Etymology

from French néphéline, from Greek nephelē

From the town of Webster located in North Carolina

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Aphanitic

Clastic, Granular, Phaneritic, Porphyritic

Color

Black, Brown, Green, Grey, White

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

Skeletal

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

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

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate

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

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)

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

Types

Peralkaline Nephelinite

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

Nephelinite 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

Clinopyroxene, Nepheline, Plagioclase

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

Compound Content

Ca, CaO, Carbon, Cl, MgO

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

6.57

1 7

👆🏻

Grain Size

Fine Grained

Coarse Grained

Fracture

Flat

Uneven

Streak

White

White, Greenish White or Grey

Porosity

Less Porous

Luster

Vitreous to Metallic

Dull to Vitreous to Submetallic

Compressive Strength

35.00 N/mm²95.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.7

Specific Gravity

2.4-2.93.2-3.5

0 8.4

👆🏻

Transparency

Opaque

Density

2.5-3 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

Japan

India, Russia

Africa

Rwanda, Tanzania

South Africa

Europe

Germany, Greece, Italy, Scotland, Turkey

Others

Hawaii Islands

Greenland

Deposits in Western Continents

North America

Canada, USA

South America

Colombia

Brazil, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Queensland

All about Nephelinite and Websterite Properties

Know all about Nephelinite and Websterite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Websterite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Websterite is Clastic, Granular, Phaneritic, Porphyritic. Nephelinite appears Skeletal and Websterite appears Layered, Banded, Veined and Shiny. The luster of Nephelinite is vitreous to metallic while that of Websterite is dull to vitreous to submetallic. Nephelinite is available in black, brown, green, grey, white colors whereas Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.