Pseudotachylite

Chert

Pseudotachylite and Chert

Pseudotachylite

Chert

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1 Definition

1.1 Definition

Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.

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

1.2 History

1.2.1 Origin

USA

Unknown

1.2.2 Discoverer

Unknown

1.3 Etymology

From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.

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

1.4 Class

Metamorphic Rocks

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Quench

Banded, Rough

2.2 Color

Black, Brown, Colourless, Green, Grey, Pink, White

Black, Brown, Green, Grey, Red, White

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

Dull and Soft

Glassy or Pearly

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Homes

3.1.2 Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone

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

4 Types

4.1 Types

Not Available

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

4.2 Features

Host Rock for Lead

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

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

Present

5 Formation

5.1 Formation

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

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.

5.2 Composition

5.2.1 Mineral Content

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Quartz, Silicon

5.2.2 Compound Content

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Not Applicable

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

76.5-7

1 7

6.1.2 Grain Size

Very fine-grained

6.1.3 Fracture

Uneven

Uneven, Splintery or Conchoidal

6.1.4 Streak

Light to dark brown

White

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Vitreous

Waxy and Dull

6.1.7 Compressive Strength

60.00 N/mm²450.00 N/mm²

0.15 450

6.1.8 Cleavage

Irregular

Non-Existent

6.1.9 Toughness

Not Available

1.5

6.1.10 Specific Gravity

2.46-2.862.5-2.8

0 8.4

6.1.11 Transparency

Transparent to Translucent

Translucent to Opaque

6.1.12 Density

2.7-2.9 g/cm³2.7 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.74 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

South Korea

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

7.1.2 Africa

Western Africa

Kenya, Morocco, South Africa, Tanzania

7.1.3 Europe

Great Britain, Switzerland

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

7.1.4 Others

Not Yet Found

Greenland, Mid-Atlantic Ridge

7.2 Deposits in Western Continents

7.2.1 North America

Not Yet Found

Canada, Mexico, USA

7.2.2 South America

Not Yet Found

Bolivia, Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Central Australia, Western Australia

New South Wales, Queensland, South Australia, Western Australia

All about Pseudotachylite and Chert Properties

Know all about Pseudotachylite and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite belongs to Metamorphic Rocks while Chert belongs to Sedimentary Rocks.Texture of Pseudotachylite is Quench whereas that of Chert is Banded, Rough. Pseudotachylite appears Dull and Soft and Chert appears Glassy or Pearly. The luster of Pseudotachylite is vitreous while that of Chert is waxy and dull. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas Chert is available in black, brown, green, grey, red, white colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.