Variolite

Tuff

Variolite vs Tuff

Variolite

Tuff

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1 Definition

1.1 Definition

Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance

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

1.2 History

1.2.1 Origin

France

Italy

1.2.2 Discoverer

Unknown

1.3 Etymology

From Latin varius, speckled, variegated

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

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Clastic, Pyroclastic

2.2 Color

Black, Brown, Light to Dark Grey

Brown, Grey, Yellow

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

81% Igneous Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

86% Igneous Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

66% Igneous Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

49% Igneous Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

48% Igneous Rocks Rocks have it !

2.5 Appearance

Dull and Soft

Dull, Vesicular and Foilated

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Office Buildings

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Building houses or walls, Construction Aggregate

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork

4 Types

4.1 Types

Not Available

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

4.2 Features

Has High structural resistance against erosion and climate, Very fine grained rock

Always found as volcanic pipes over deep continental crust

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

Easter Island in the Polynesian Triangle, Pacific Ocean

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.

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.

5.2 Composition

5.2.1 Mineral Content

Olivine, Plagioclase, Pyroxene

Calcite, Chlorite

5.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Hydrogen Sulfide, Sulfur Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

97% Igneous Rocks Rocks have it !

5.3.2 Types of Metamorphism

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

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

99% Igneous Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

92% Igneous Rocks Rocks have it !

5.3.6 Types of Erosion

Not Applicable

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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

4-6

6.1.2 Grain Size

Not Applicable

Fine Grained

6.1.3 Fracture

Conchoidal

Uneven

6.1.4 Streak

White to Grey

White

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Not Available

Vitreous to Dull

6.1.7 Compressive Strength

Flint

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▶

▼

37.50 N/mm²

Rank: 27 (Overall)▶

243.80 N/mm²

Rank: 5 (Overall)▶

▲

Obsidian

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▶

175 (Granite)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Not Available

6.1.9 Toughness

2.3

Not Available

6.1.10 Specific Gravity

2.8-3

2.73

6.1.11 Transparency

Opaque

6.1.12 Density

2.9-3.1 g/cm³

1-1.8 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

Banded iron for..

⊕

▶

▼

0.84 kJ/Kg K

Rank: 15 (Overall)▶

0.20 kJ/Kg K

Rank: 25 (Overall)▶

▲

Granulite

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▶

1.09 (Travertine)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Russia

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

7.1.2 Africa

South Africa

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

7.1.3 Europe

Iceland

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

7.1.4 Others

Not Yet Found

Antarctica, Hawaii Islands

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Costa Rica, Panama, USA

7.2.2 South America

Brazil

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

Central Australia, Western Australia

Variolite vs Tuff Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Variolite and Tuff Reserves. Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance. Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Variolite vs Tuff information and Variolite vs Tuff characteristics in the upcoming sections.

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Variolite vs Tuff Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Variolite vs Tuff characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Tuff. Learn more about Variolite vs Tuff in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Tuff include Decorative aggregates, Entryways, Flooring, Homes and Interior decoration. Due to some exceptional properties of Variolite and Tuff, they have various applications in construction industry. The uses of Variolite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Tuff include Building houses or walls, Construction aggregate.

More about Variolite and Tuff

Here you can know more about Variolite and Tuff. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Tuff consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Tuff includes Calcite, Chlorite. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Tuff, the texture, color and appearance plays an important role in determining the type of rock. Variolite is available in black, brown, light to dark grey colors whereas, Tuff is available in brown, grey, yellow colors. Appearance of Variolite is Dull and Soft and that of Tuff is Dull, Vesicular and Foilated. Properties of rock is another aspect for Variolite vs Tuff. The hardness of Variolite is 6 and that of Tuff is 4-6. The types of Variolite are Not Available whereas types of Tuff are Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Variolite is white to grey while that of Tuff is white. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Tuff is 0.20 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Variolite is heat resistant, pressure resistant, wear resistant whereas Tuff is heat resistant, impact resistant, pressure resistant, wear resistant.