Tuff

Pseudotachylite

Tuff and Pseudotachylite

Tuff

Pseudotachylite

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1 Definition

1.1 Definition

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

Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.

1.2 History

1.2.1 Origin

Italy

USA

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Clastic, Pyroclastic

Quench

2.2 Color

Brown, Grey, Yellow

Black, Brown, Colourless, Green, Grey, Pink, White

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Dull, Vesicular and Foilated

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

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

As Building Stone, As Facing Stone, Garden Decoration

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Building houses or walls, Construction Aggregate

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork

Creating Artwork, Gemstone

4 Types

4.1 Types

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

Not Available

4.2 Features

Always found as volcanic pipes over deep continental crust

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

Data Not Available

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

5.2 Composition

5.2.1 Mineral Content

Calcite, Chlorite

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

5.2.2 Compound Content

Hydrogen Sulfide, Sulfur Dioxide

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

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

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

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

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

4-67

1 7

6.1.2 Grain Size

Fine Grained

Very fine-grained

6.1.3 Fracture

Uneven

6.1.4 Streak

White

Light to dark brown

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Vitreous to Dull

Vitreous

6.1.7 Compressive Strength

243.80 N/mm²60.00 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Irregular

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.732.46-2.86

0 8.4

6.1.11 Transparency

Opaque

Transparent to Translucent

6.1.12 Density

1-1.8 g/cm³2.7-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.20 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 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

South Korea

7.1.2 Africa

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

Western Africa

7.1.3 Europe

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

Great Britain, Switzerland

7.1.4 Others

Antarctica, Hawaii Islands

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Costa Rica, Panama, USA

Not Yet Found

7.2.2 South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

Central Australia, Western Australia

All about Tuff and Pseudotachylite Properties

Know all about Tuff and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Tuff belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Pseudotachylite is Quench. Tuff appears Dull, Vesicular and Foilated and Pseudotachylite appears Dull and Soft. The luster of Tuff is vitreous to dull while that of Pseudotachylite is vitreous. Tuff is available in brown, grey, yellow colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Tuff are creating artwork and that of Pseudotachylite are creating artwork, gemstone.