Pumice

Obsidian

Pumice and Obsidian

Pumice

Obsidian

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1 Definition

1.1 Definition

Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth

1.2 History

1.2.1 Origin

Spain

Ethiopia

1.2.2 Discoverer

Unknown

Obsius

1.3 Etymology

From Old French pomis, from a Latin dialect variant of pumex

From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Vesicular

Glassy

2.2 Color

Beige, Colourless, Grey, Light Green, Light Grey, Pink, White, Yellow- grey

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Vesicular

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

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

Garden Decoration

3.1.3 Other Architectural Uses

Curbing, Powder

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cement Manufacture, for Road Aggregate, In landscaping and horticulture, Making natural cement, Production of lightweight concrete blocks

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

As an abrasive in skin exfoliating products, In Chemical and Pharmaceutical Industry, Medicines and Cosmetics

Surgery

3.3 Antiquity Uses

Artifacts

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

As a traction material on snow-covered roads, As an abrasive in pencil erasers, Fine abrasive used for polishing, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Used in aquariums

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Scoria

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

4.2 Features

Host Rock for Lead

Blocks negativity, Helps to protect against depression

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Pumice rock forms when the magma cools so quickly that atoms in the melt are not able to arrange themselves into a crystalline structure.

When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.

5.2 Composition

5.2.1 Mineral Content

Aluminum Oxides, Calcite, Carbonate, Iron Oxides, Silica

Not Available

5.2.2 Compound Content

Al, Aluminium Oxide, CaO, Carbon Dioxide, MgO, Silicon Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Impact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

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

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

65-5.5

1 7

6.1.2 Grain Size

Fine Grained

Not Applicable

6.1.3 Fracture

Planar

Conchoidal

6.1.4 Streak

White, Greenish White or Grey

White

6.1.5 Porosity

Highly Porous

Very Less Porous

6.1.6 Luster

Earthy

Vitreous

6.1.7 Compressive Strength

51.20 N/mm²0.15 N/mm²

0.15 450

6.1.8 Cleavage

Perfect

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.862.6-2.7

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

0.25-0.3 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.87 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

Ethiopia, Kenya, Tanzania

Kenya

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA

Canada, Mexico, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, Western Australia

New Zealand

All about Pumice and Obsidian Properties

Know all about Pumice and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Pumice and Obsidian belong to Igneous Rocks.Texture of Pumice is Vesicular whereas that of Obsidian is Glassy. Pumice appears Vesicular and Obsidian appears Shiny. The luster of Pumice is earthy while that of Obsidian is vitreous. Pumice is available in beige, colourless, grey, light green, light grey, pink, white, yellow- grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Pumice are as a traction material on snow-covered roads, as an abrasive in pencil erasers, fine abrasive used for polishing, manufacture of soap, solvents, dyes, plastics and fibres, used in aquariums and that of Obsidian are creating artwork, mirror, used in aquariums.