Tephrite

Websterite

Tephrite and Websterite

Tephrite

Websterite

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Definition

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

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

Germany

Webster, North Carolina

Discoverer

Van Tooren

Unknown

Etymology

From Greek tephra, ashes from Indo-European base, to burn

From the town of Webster located in North Carolina

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

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

Vesicular

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

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

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Landscaping

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

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts

Other Uses

Commercial Uses

Production of Lime, Soil Conditioner

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

Types

Igneous rock

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

Tephrite 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

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

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

Compound Content

CaO, Carbon Dioxide, MgO, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

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

Properties

Physical Properties

Hardness

6.57

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Coarse Grained

Fracture

Uneven

Streak

Bluish Black

White, Greenish White or Grey

Porosity

Very Less Porous

Less Porous

Luster

Subvitreous to Dull

Dull to Vitreous to Submetallic

Compressive Strength

90.00 N/mm²95.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

2.4

Specific Gravity

2.863.2-3.5

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³3.1-3.6 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Africa

Namibia, Uganda

South Africa

Europe

Germany, Hungary, Italy, Portugal, Spain

Germany, Greece, Italy, Scotland, Turkey

Others

Greenland

Deposits in Western Continents

North America

USA

Canada, USA

South America

Brazil, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New Zealand, Queensland

All about Tephrite and Websterite Properties

Know all about Tephrite and Websterite properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite and Websterite belong to Igneous Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Websterite is Clastic, Granular, Phaneritic, Porphyritic. Tephrite appears Vesicular and Websterite appears Layered, Banded, Veined and Shiny. The luster of Tephrite is subvitreous to dull while that of Websterite is dull to vitreous to submetallic. Tephrite 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 Tephrite are production of lime, soil conditioner and that of Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.