Chert

Websterite

Chert and Websterite

Chert

Websterite

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1 Definition

1.1 Definition

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

Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.

1.2 History

1.2.1 Origin

Unknown

Webster, North Carolina

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From the town of Webster located in North Carolina

1.4 Class

Sedimentary Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

Plutonic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Banded, Rough

Clastic, Granular, Phaneritic, Porphyritic

2.2 Color

Black, Brown, Green, Grey, Red, White

Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

59% Sedimentary Rocks Rocks have it !

✔ ✘

81% Igneous Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

62% Sedimentary Rocks Rocks have it !

✔ ✘

86% Igneous Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

43% Sedimentary Rocks Rocks have it !

✔ ✘

66% Igneous Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

38% Sedimentary Rocks Rocks have it !

✔ ✘

49% Igneous Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

22% Sedimentary Rocks Rocks have it !

✔ ✘

48% Igneous Rocks Rocks have it !

2.5 Appearance

Glassy or Pearly

Layered, Banded, Veined and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes

Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Interior Decoration

3.1.2 Exterior Uses

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

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

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

Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones

4 Types

4.1 Types

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

Not Available

4.2 Features

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

Generally rough to touch, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Present

Absent

5 Formation

5.1 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.

Websterite can be formed as cumulates in ultramafic intrusions by accumulation of pyroxene crystals at the base of the lava chamber.

5.2 Composition

5.2.1 Mineral Content

Quartz, Silicon

Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene

5.2.2 Compound Content

Silicon Dioxide

Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

19% Sedimentary Rocks Rocks have it !

✔ ✘

97% Igneous Rocks Rocks have it !

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Impact Metamorphism

5.3.3 Weathering

✔ ✘

78% Sedimentary Rocks Rocks have it !

✔ ✘

99% Igneous Rocks Rocks have it !

5.3.4 Types of Weathering

Not Applicable

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

86% Sedimentary Rocks Rocks have it !

✔ ✘

92% Igneous Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion

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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.5-7

6.1.2 Grain Size

Very fine-grained

Coarse Grained

6.1.3 Fracture

Uneven, Splintery or Conchoidal

Uneven

6.1.4 Streak

White

White, Greenish White or Grey

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Waxy and Dull

Dull to Vitreous to Submetallic

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

450.00 N/mm²

Rank: 1 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Non-Existent

Irregular

6.1.9 Toughness

1.5

Not Available

6.1.10 Specific Gravity

2.5-2.8

3.2-3.5

6.1.11 Transparency

Translucent to Opaque

Opaque

6.1.12 Density

2.7 g/cm³

3.1-3.6 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.74 kJ/Kg K

Rank: 19 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

India, Russia

7.1.2 Africa

Kenya, Morocco, South Africa, Tanzania

South Africa

7.1.3 Europe

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

Germany, Greece, Italy, Scotland, Turkey

7.1.4 Others

Greenland, Mid-Atlantic Ridge

Greenland

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, USA

7.2.2 South America

Bolivia, Brazil

Brazil, Colombia, Venezuela

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, Queensland, South Australia, Western Australia

New Zealand, Queensland

All about Chert and Websterite Properties

Know all about Chert and Websterite properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Websterite belongs to Igneous Rocks.Texture of Chert is Banded, Rough whereas that of Websterite is Clastic, Granular, Phaneritic, Porphyritic. Chert appears Glassy or Pearly and Websterite appears Layered, Banded, Veined and Shiny. The luster of Chert is waxy and dull while that of Websterite is dull to vitreous to submetallic. Chert is available in black, brown, green, grey, red, white colors whereas Websterite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey 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 Websterite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.