Pumice

Chert

Pumice and Chert

Pumice

Chert

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Definition

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

Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture

History

Origin

Spain

Discoverer

Unknown

Etymology

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

From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use

Class

Igneous Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Vesicular

Banded, Rough

Color

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

Black, Brown, Green, Grey, Red, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Glassy or Pearly

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Homes

Exterior Uses

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

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

Other Architectural Uses

Curbing, Powder

Curbing

Industry

Construction Industry

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

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

Medical Industry

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

Antiquity Uses

Artifacts

Artifacts, Monuments

Other Uses

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, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms

Types

Scoria

Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter

Features

Host Rock for Lead

Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

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.

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

Composition

Mineral Content

Aluminum Oxides, Calcite, Carbonate, Iron Oxides, Silica

Quartz, Silicon

Compound Content

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

Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Impact 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

Chemical Erosion

Properties

Physical Properties

Hardness

66.5-7

1 7

👆🏻

Grain Size

Fine Grained

Very fine-grained

Fracture

Planar

Uneven, Splintery or Conchoidal

Streak

White, Greenish White or Grey

White

Porosity

Highly Porous

Luster

Earthy

Waxy and Dull

Compressive Strength

51.20 N/mm²450.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.5

Specific Gravity

2.862.5-2.8

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

0.25-0.3 g/cm³2.7 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.87 kJ/Kg K0.74 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

Africa

Ethiopia, Kenya, Tanzania

Kenya, Morocco, South Africa, Tanzania

Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

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

Canada, Mexico, USA

South America

Argentina, Chile, Ecuador, Peru

Bolivia, Brazil

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New South Wales, Queensland, South Australia, Western Australia

All about Pumice and Chert Properties

Know all about Pumice and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Pumice belongs to Igneous Rocks while Chert belongs to Sedimentary Rocks.Texture of Pumice is Vesicular whereas that of Chert is Banded, Rough. Pumice appears Vesicular and Chert appears Glassy or Pearly. The luster of Pumice is earthy while that of Chert is waxy and dull. Pumice is available in beige, grey, light green, light grey, pink, white, yellow- grey colors whereas Chert is available in black, brown, green, grey, red, white 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 Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.