Tuff and Blueschist

Tuff

Blueschist

Definition

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

Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature

History

Origin

Italy

USA

Discoverer

Unknown

Edgar Bailey

Etymology

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

From French schiste, Greek skhistos i.e. split

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Not Applicable

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Clastic, Pyroclastic

Foliated

Color

Brown, Grey, Yellow

Blue, Bluish - Grey, Purple, Shades of Blue

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Wind Resistant

Acid Resistant

Appearance

Dull, Vesicular and Foilated

Dull and Banded

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Exterior Uses

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

Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Not Yet Used

Industry

Construction Industry

Building houses or walls, Construction Aggregate

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones

Types

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

Not Available

Features

Always found as volcanic pipes over deep continental crust

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

Archaeological Significance

Monuments

Used

Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

Data Not Available

Sculpture

Used

Famous Sculptures

Data Not Available

Pictographs

Used

Petroglyphs

Used

Figurines

Used

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.

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

Composition

Mineral Content

Calcite, Chlorite

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

Compound Content

Hydrogen Sulfide, Sulfur Dioxide

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

Transformation

Metamorphism

Yes

Types of Metamorphism

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

Not Applicable

Weathering

Yes

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Mechanical Weathering

Erosion

Yes

Types of Erosion

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

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

4-6

3.5-4

Grain Size

Fine Grained

Fine to Medium Grained

Fracture

Uneven

Conchoidal

Streak

White

White to Grey

Porosity

Highly Porous

Luster

Vitreous to Dull

Dull

Compressive Strength

243.80 N/mm²

Not Available

Cleavage

Not Available

Slaty

Toughness

Not Available

1.5

Specific Gravity

2.73

3-3.2

Transparency

Opaque

Density

1-1.8 g/cm³

2.8-2.9 g/cm³

Thermal Properties

Specific Heat Capacity

0.20 kJ/Kg K

Not Available

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Impact Resistant, Pressure 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

Japan, Turkey

Africa

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

Egypt, Ethiopia, South Africa

Europe

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

France, Greece, Iceland

Others

Antarctica, Hawaii Islands

Not Yet Found

Deposits in Western Continents

North America

Canada, Costa Rica, Panama, USA

USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Not Yet Found

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New Zealand

Summary >>

<< Reserves

All about Tuff and Blueschist Properties

Know all about Tuff and Blueschist properties here. All properties of rocks are important as they define the type of rock and its application. Tuff belongs to Igneous Rocks while Blueschist belongs to Metamorphic Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Blueschist is Foliated. Tuff appears Dull, Vesicular and Foilated and Blueschist appears Dull and Banded. The luster of Tuff is vitreous to dull while that of Blueschist is dull. Tuff is available in brown, grey, yellow colors whereas Blueschist is available in blue, bluish - grey, purple, shades of blue colors. The commercial uses of Tuff are creating artwork and that of Blueschist are cemetery markers, commemorative tablets, creating artwork, curling, tombstones.