Tuff

Mylonite

Tuff and Mylonite

Tuff

Mylonite

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Definition

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

Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism

History

Origin

Italy

New Zealand

Discoverer

Unknown

Etymology

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

From Greek mulōn mill + -ite

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic, Pyroclastic

Foliated

Color

Brown, Grey, Yellow

Black to Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull, Vesicular and Foilated

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Construction Aggregate

for Road Aggregate, Landscaping, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments

Other Uses

Commercial Uses

Creating Artwork

Creating Artwork, Gemstone, Jewelry

Types

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

Blastomylonites, Ultramylonites and Phyllonites

Features

Always found as volcanic pipes over deep continental crust

Surfaces are often shiny

Archaeological Significance

Monuments

Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

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.

Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.

Composition

Mineral Content

Calcite, Chlorite

Porphyroblasts

Compound Content

Hydrogen Sulfide, Sulfur Dioxide

Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

4-63-4

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Uneven

Conchoidal

Streak

White

Porosity

Highly Porous

Luster

Vitreous to Dull

Shiny

Compressive Strength

243.80 N/mm²1.28 N/mm²

0.15 450

👆🏻

Cleavage

Conchoidal

Toughness

Specific Gravity

2.732.97-3.05

0 8.4

👆🏻

Transparency

Opaque

Density

1-1.8 g/cm³2.6-4.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.20 kJ/Kg K1.50 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat 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

China, India, Indonesia, Saudi Arabia, South Korea

Africa

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

Eritrea, Ethiopia, Ghana, South Africa, Western Africa

Europe

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

England, Finland, France, Germany, Great Britain, Greece, United Kingdom

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

Canada, Costa Rica, Panama, USA

USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

All about Tuff and Mylonite Properties

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