Tuff

Porphyry

Tuff and Porphyry

Tuff

Porphyry

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Definition

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

Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix

History

Origin

Italy

Egypt

Discoverer

Unknown

Etymology

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

From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic, Pyroclastic

Porphyritic

Color

Brown, Grey, Yellow

Black, Brown, Green, Grey, Red, Rust, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull, Vesicular and Foilated

Dull

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

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Construction Aggregate

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Creating Artwork

Creating Artwork, Gemstone, Jewelry

Types

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

Rhomb Porphyry

Features

Always found as volcanic pipes over deep continental crust

Generally rough to touch, Is one of the oldest rock, 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.

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

Composition

Mineral Content

Calcite, Chlorite

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

Compound Content

Hydrogen Sulfide, Sulfur Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium 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

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

4-66-7

1 7

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Grain Size

Fine Grained

Fracture

Uneven

Irregular

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Vitreous to Dull

Dull

Compressive Strength

243.80 N/mm²150.00 N/mm²

0.15 450

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Cleavage

Toughness

1.7

Specific Gravity

2.732.5-4

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

1-1.8 g/cm³2.5-2.52 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.20 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact 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, Kazakhstan, South Korea, Thailand, Turkey, Vietnam

Africa

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

Egypt, Ethiopia, Ghana, South Africa

Europe

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

Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland

Others

Antarctica, Hawaii Islands

Greenland

Deposits in Western Continents

North America

Canada, Costa Rica, Panama, USA

Canada, Cuba, Jamaica, USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New South Wales, New Zealand, Western Australia

All about Tuff and Porphyry Properties

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