Tuff

Pegmatite

Tuff and Pegmatite

Tuff

Pegmatite

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Definition

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

Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals

History

Origin

Italy

Discoverer

Unknown

R. J. Hauy

Etymology

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

From Greek pegma, pegmat which means- thing joined together + -ite

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

Coarse Grained Rock, Opaque Rock

Texture

Clastic, Pyroclastic

Pegmatitic

Color

Brown, Grey, Yellow

Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull, Vesicular and Foilated

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Construction Aggregate

As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork

Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz

Types

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

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Features

Always found as volcanic pipes over deep continental crust

Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz

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.

Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.

Composition

Mineral Content

Calcite, Chlorite

Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz

Compound Content

Hydrogen Sulfide, Sulfur Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide

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

Properties

Physical Properties

Hardness

4-67

1 7

👆🏻

Grain Size

Fine Grained

Medium to Coarse Grained

Fracture

Uneven

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Vitreous to Dull

Grainy, Pearly and Vitreous

Compressive Strength

243.80 N/mm²178.54 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

Specific Gravity

2.732.6-2.63

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

1-1.8 g/cm³2.6-2.65 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.20 kJ/Kg K0.79 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, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea

Africa

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

South Africa

Europe

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

Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

Canada, Costa Rica, Panama, USA

Canada

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Brazil

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New South Wales, Queensland, South Australia, Western Australia

All about Tuff and Pegmatite Properties

Know all about Tuff and Pegmatite properties here. All properties of rocks are important as they define the type of rock and its application. Tuff and Pegmatite belong to Igneous Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Pegmatite is Pegmatitic. Tuff appears Dull, Vesicular and Foilated and Pegmatite appears Layered, Banded, Veined and Shiny. The luster of Tuff is vitreous to dull while that of Pegmatite is grainy, pearly and vitreous. Tuff is available in brown, grey, yellow colors whereas Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Tuff are creating artwork and that of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz.