Tuff

Picrite

Tuff and Picrite

Tuff

Picrite

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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

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

1.2 History

1.2.1 Origin

Italy

Hawaii Islands

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From Greek pikros bitter + -ite, 19th century

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Clastic, Pyroclastic

Earthy, Rough

2.2 Color

Brown, Grey, Yellow

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

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

Rough and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Countertops, Decorative Aggregates, Homes, 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, Paving Stone

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Building houses or walls, Construction Aggregate

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

4 Types

4.1 Types

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

Oceanite

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

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

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.

Picrite 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.

5.2 Composition

5.2.1 Mineral Content

Calcite, Chlorite

Biotite, Olivine, Plagioclase, Pyrrhotite

5.2.2 Compound Content

Hydrogen Sulfide, Sulfur Dioxide

Al, CaO, Carbon Dioxide, Mg, MgO

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, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

4-66.8

1 7

6.1.2 Grain Size

Fine Grained

6.1.3 Fracture

Uneven

6.1.4 Streak

White

White, Greenish White or Grey

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Vitreous to Dull

Subvitreous to Dull

6.1.7 Compressive Strength

243.80 N/mm²189.00 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Imperfect

6.1.9 Toughness

Not Available

2.1

6.1.10 Specific Gravity

2.732.75-2.92

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

1-1.8 g/cm³1.5-2.5 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.20 kJ/Kg K0.88 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

India, Russia

7.1.2 Africa

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

South Africa

7.1.3 Europe

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

Iceland

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

Canada, USA

7.2.2 South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Central Australia, Western Australia

Not Yet Found

All about Tuff and Picrite Properties

Know all about Tuff and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Tuff and Picrite belong to Igneous Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Picrite is Earthy, Rough. Tuff appears Dull, Vesicular and Foilated and Picrite appears Rough and Shiny. The luster of Tuff is vitreous to dull while that of Picrite is subvitreous to dull. Tuff is available in brown, grey, yellow colors whereas Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors. The commercial uses of Tuff are creating artwork and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).