Chert

Oolite

Chert and Oolite

Chert

Oolite

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Definition

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

Oolite is a sedimentary rock formed from ooids, spherical grains which are composed of concentric layers of calcite

History

Origin

Discoverer

Unknown

William Smith

Etymology

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

From oo- + -lite, after German Oolit. A rock consisting of fine grains of carbonate of lime

Class

Sedimentary Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Banded, Rough

Clastic or Non-Clastic

Color

Black, Brown, Green, Grey, Red, White

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Glassy or Pearly

Rounded and Rough

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

Cement Manufacture, Cobblestones, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

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

Creating Artwork, Jewelry, Used in aquariums

Types

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

Pisolitic Oolite and Oncolitic Oolite

Features

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

Available in lots of colors, Generally rough to touch, Very fine grained rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Formation

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.

Oolites form when layers of calcite are deposited around a sand grain or fossil piece and are rolled around in calm water, which makes them round.

Composition

Mineral Content

Quartz, Silicon

Calcite, Chert, Clay, Dolomite, Quartz, Sand, Silt

Compound Content

Silicon Dioxide

Aluminium Oxide, Ca, NaCl, CaO, Iron(III) Oxide, FeO, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion

Properties

Physical Properties

Hardness

6.5-73-4

1 7

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Grain Size

Very fine-grained

Fine Grained

Fracture

Uneven, Splintery or Conchoidal

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Waxy and Dull

Pearly to Shiny

Compressive Strength

450.00 N/mm²40.00 N/mm²

0.15 450

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Cleavage

Toughness

1.5

Specific Gravity

2.5-2.8-9999

0 8.4

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Transparency

Translucent to Opaque

Opaque

Density

2.7 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.74 kJ/Kg K0.65 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam

Africa

Kenya, Morocco, South Africa, Tanzania

Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe

Europe

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

United Kingdom

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Bolivia, Brazil

Colombia

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula

All about Chert and Oolite Properties

Know all about Chert and Oolite properties here. All properties of rocks are important as they define the type of rock and its application. Chert and Oolite belong to Sedimentary Rocks.Texture of Chert is Banded, Rough whereas that of Oolite is Clastic or Non-Clastic. Chert appears Glassy or Pearly and Oolite appears Rounded and Rough. The luster of Chert is waxy and dull while that of Oolite is pearly to shiny. Chert is available in black, brown, green, grey, red, white colors whereas Oolite is available in black, blue, brown, cream, green, grey, pink, red, silver, white, yellow colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Oolite are creating artwork, jewelry, used in aquariums.