Tephrite

Tuff

Tephrite and Tuff

Tephrite

Tuff

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Definition

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption

History

Origin

Germany

Italy

Discoverer

Van Tooren

Unknown

Etymology

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

From a Latin word tophous then in Italian tufo and finally tuff

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Clastic, Pyroclastic

Color

Black, Brown, Green, Grey, White

Brown, Grey, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Landscaping

Building houses or walls, Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Production of Lime, Soil Conditioner

Creating Artwork

Types

Igneous rock

Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.

Features

Host Rock for Lead

Always found as volcanic pipes over deep continental crust

Archaeological Significance

Monuments

Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

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.

Tuff is formed when large masses of ash and sand which are mixed with hot gases are ejected by a volcano and avalanche rapidly down its slopes.

Composition

Mineral Content

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Calcite, Chlorite

Compound Content

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Hydrogen Sulfide, Sulfur Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional 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, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6.54-6

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Uneven

Streak

Bluish Black

White

Porosity

Very Less Porous

Highly Porous

Luster

Subvitreous to Dull

Vitreous to Dull

Compressive Strength

90.00 N/mm²243.80 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

2.4

Specific Gravity

2.862.73

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³1-1.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.20 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen

Africa

Namibia, Uganda

Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda

Europe

Germany, Hungary, Italy, Portugal, Spain

France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

USA

Canada, Costa Rica, Panama, USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

Central Australia, Western Australia

All about Tephrite and Tuff Properties

Know all about Tephrite and Tuff properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite and Tuff belong to Igneous Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Tuff is Clastic, Pyroclastic. Tephrite appears Vesicular and Tuff appears Dull, Vesicular and Foilated. The luster of Tephrite is subvitreous to dull while that of Tuff is vitreous to dull. Tephrite is available in black, brown, green, grey, white colors whereas Tuff is available in brown, grey, yellow colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Tuff are creating artwork.