Tuff

Tephrite

Tuff and Tephrite

Tuff

Tephrite

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Definition

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

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

History

Origin

Italy

Germany

Discoverer

Unknown

Van Tooren

Etymology

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

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

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

Texture

Clastic, Pyroclastic

Aphanitic to Porphyritic

Color

Brown, Grey, Yellow

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull, Vesicular and Foilated

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Construction Aggregate

Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Sculpture

Other Uses

Commercial Uses

Creating Artwork

Production of Lime, Soil Conditioner

Types

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

Igneous rock

Features

Always found as volcanic pipes over deep continental crust

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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.

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.

Composition

Mineral Content

Calcite, Chlorite

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Compound Content

Hydrogen Sulfide, Sulfur Dioxide

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Cataclastic Metamorphism, Contact 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, Wind Erosion

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

Properties

Physical Properties

Hardness

4-66.5

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Uneven

Streak

White

Bluish Black

Porosity

Highly Porous

Very Less Porous

Luster

Vitreous to Dull

Subvitreous to Dull

Compressive Strength

243.80 N/mm²90.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

2.4

Specific Gravity

2.732.86

0 8.4

👆🏻

Transparency

Opaque

Density

1-1.8 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.20 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact 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

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

Namibia, Uganda

Europe

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

Germany, Hungary, Italy, Portugal, Spain

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

Canada, Costa Rica, Panama, USA

USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New Zealand, Western Australia

All about Tuff and Tephrite Properties

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