Tuff and Slate

Tuff

Slate

Definition

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

Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism

History

Origin

Italy

England

Discoverer

Unknown

Etymology

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

From Old French esclate, from esclat (French éclat)

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Not Applicable

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic, Pyroclastic

Foliated

Color

Brown, Grey, Yellow

Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Yes

Wind Resistant

Acid Resistant

Appearance

Dull, Vesicular and Foilated

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Construction Aggregate

As Dimension Stone

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork

Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates

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

Easily splits into thin plates, Surfaces are often shiny, 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.

Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.

Composition

Mineral Content

Calcite, Chlorite

Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon

Compound Content

Hydrogen Sulfide, Sulfur Dioxide

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

Transformation

Metamorphism

Yes

Types of Metamorphism

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

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Weathering

Yes

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

Yes

Types of Erosion

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

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

4-6

3-4

Grain Size

Fine Grained

Very fine-grained

Fracture

Uneven

Splintery

Streak

White

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Vitreous to Dull

Dull

Compressive Strength

243.80 N/mm²

30.00 N/mm²

Cleavage

Not Available

Slaty

Toughness

Not Available

1.2

Specific Gravity

2.73

2.65-2.8

Transparency

Opaque

Density

1-1.8 g/cm³

2.6-2.8 g/cm³

Thermal Properties

Specific Heat Capacity

0.20 kJ/Kg K

0.76 kJ/Kg K

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear 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, Turkey

Africa

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

Not Yet Found

Europe

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

Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom

Others

Antarctica, Hawaii Islands

Arctic

Deposits in Western Continents

North America

Canada, Costa Rica, Panama, USA

USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Brazil

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

Not Yet Found

Summary >>

<< Reserves

All about Tuff and Slate Properties

Know all about Tuff and Slate properties here. All properties of rocks are important as they define the type of rock and its application. Tuff belongs to Igneous Rocks while Slate belongs to Metamorphic Rocks.Texture of Tuff is Clastic, Pyroclastic whereas that of Slate is Foliated. Tuff appears Dull, Vesicular and Foilated and Slate appears Dull. The luster of Tuff is vitreous to dull while that of Slate is dull. Tuff is available in brown, grey, yellow colors whereas Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors. The commercial uses of Tuff are creating artwork and that of Slate are blackboards, commemorative tablets, laboratory bench tops, standard material for the bed of billiard table, standard material for the beds of pool and snooker table, tombstones, used in aquariums, writing slates.