Tuff

Chert

Tuff and Chert

Tuff

Chert

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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

Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture

1.2 History

1.2.1 Origin

Italy

Unknown

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use

1.4 Class

Igneous Rocks

Sedimentary 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

Banded, Rough

2.2 Color

Brown, Grey, Yellow

Black, Brown, Green, Grey, Red, 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

Glassy or Pearly

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Homes

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, Office Buildings

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Building houses or walls, Construction Aggregate

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

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, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms

4 Types

4.1 Types

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

Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter

4.2 Features

Always found as volcanic pipes over deep continental crust

Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate

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

Present

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.

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

5.2 Composition

5.2.1 Mineral Content

Calcite, Chlorite

Quartz, Silicon

5.2.2 Compound Content

Hydrogen Sulfide, Sulfur Dioxide

Silicon Dioxide

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

Not Applicable

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

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

4-66.5-7

1 7

6.1.2 Grain Size

Fine Grained

Very fine-grained

6.1.3 Fracture

Uneven

Uneven, Splintery or Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

6.1.6 Luster

Vitreous to Dull

Waxy and Dull

6.1.7 Compressive Strength

243.80 N/mm²450.00 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Non-Existent

6.1.9 Toughness

Not Available

1.5

6.1.10 Specific Gravity

2.732.5-2.8

0 8.4

6.1.11 Transparency

Opaque

Translucent to Opaque

6.1.12 Density

1-1.8 g/cm³2.7 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.20 kJ/Kg K0.74 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear 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

China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

7.1.2 Africa

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

Kenya, Morocco, South Africa, Tanzania

7.1.3 Europe

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

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

7.1.4 Others

Antarctica, Hawaii Islands

Greenland, Mid-Atlantic Ridge

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Costa Rica, Panama, USA

Canada, Mexico, USA

7.2.2 South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Bolivia, Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Central Australia, Western Australia

New South Wales, Queensland, South Australia, Western Australia

All about Tuff and Chert Properties

Know all about Tuff and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Tuff belongs to Igneous Rocks while Chert belongs to Sedimentary Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Chert is Banded, Rough. Tuff appears Dull, Vesicular and Foilated and Chert appears Glassy or Pearly. The luster of Tuff is vitreous to dull while that of Chert is waxy and dull. Tuff is available in brown, grey, yellow colors whereas Chert is available in black, brown, green, grey, red, white colors. The commercial uses of Tuff are creating artwork and that of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.