Rhyolite

Tuff

Rhyolite and Tuff

Rhyolite

Tuff

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Definition

Rhyolite is a fine-grained igneous rock which is rich in silica

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

History

Origin

North America

Italy

Discoverer

Ferdinand von Richthofen

Unknown

Etymology

From German Rhyolit, from Greek rhuax lava stream + lithos stone

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Aphanitic, Glassy, Porphyritic

Clastic, Pyroclastic

Color

Grey, White, Light Black

Brown, Grey, Yellow

Maintenance

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives

Building houses or walls, Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Gemstone, Laboratory bench tops, Jewelry

Creating Artwork

Types

Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.

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

Features

Acidic in nature, Available in lots of colors

Always found as volcanic pipes over deep continental crust

Archaeological Significance

Monuments

Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.

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.

Composition

Mineral Content

Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz

Calcite, Chlorite

Compound Content

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium

Hydrogen Sulfide, Sulfur Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional 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, Sea Erosion, Water Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

6-74-6

1 7

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Grain Size

Large and Coarse Grained

Fine Grained

Fracture

Sub-conchoidal

Uneven

Streak

White

Porosity

Highly Porous

Luster

Earthy

Vitreous to Dull

Compressive Strength

140.00 N/mm²243.80 N/mm²

0.15 450

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Cleavage

Toughness

Specific Gravity

2.65-2.672.73

0 8.4

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Transparency

Opaque

Density

2.4-2.6 g/cm³1-1.8 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.20 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India

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

Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

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

Europe

Germany, Iceland, Ireland, Italy, Spain

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

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

Canada, Costa Rica, Panama, USA

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New Zealand, Queensland, Western Australia

Central Australia, Western Australia

All about Rhyolite and Tuff Properties

Know all about Rhyolite and Tuff properties here. All properties of rocks are important as they define the type of rock and its application. Rhyolite and Tuff belong to Igneous Rocks.Texture of Rhyolite is Aphanitic, Glassy, Porphyritic whereas that of Tuff is Clastic, Pyroclastic. Rhyolite appears Banded and Tuff appears Dull, Vesicular and Foilated. The luster of Rhyolite is earthy while that of Tuff is vitreous to dull. Rhyolite is available in grey, white, light black colors whereas Tuff is available in brown, grey, yellow colors. The commercial uses of Rhyolite are gemstone, laboratory bench tops, jewelry and that of Tuff are creating artwork.