Pseudotachylite

Felsite

Pseudotachylite and Felsite

Pseudotachylite

Felsite

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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.

Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition

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 English feldspar and -ite

1.4 Class

Metamorphic Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Quench

Arborescent Patterned, Vitreous

2.2 Color

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

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

Dull and Soft

Layered, Banded, Veined and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Flooring, 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

3.2 Industry

3.2.1 Construction Industry

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

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts, Monuments

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone

Mirror, Jewelry

4 Types

4.1 Types

Not Available

4.2 Features

Host Rock for Lead

Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

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.

Felsite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

5.2 Composition

5.2.1 Mineral Content

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Feldspar, Iron Oxides

5.2.2 Compound Content

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

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, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Not Applicable

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Not Applicable

Chemical Erosion, Glacier Erosion, Water Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

75-5.5

1 7

6.1.2 Grain Size

Very fine-grained

Fine Grained

6.1.3 Fracture

Uneven

Conchoidal

6.1.4 Streak

Light to dark brown

White

6.1.5 Porosity

Less Porous

Very Less Porous

6.1.6 Luster

Vitreous

6.1.7 Compressive Strength

60.00 N/mm²0.15 N/mm²

0.15 450

6.1.8 Cleavage

Irregular

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.46-2.862.6-2.7

0 8.4

6.1.11 Transparency

Transparent to Translucent

Translucent

6.1.12 Density

2.7-2.9 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

South Korea

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

Western Africa

Kenya

7.1.3 Europe

Great Britain, Switzerland

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

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

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

Central Australia, Western Australia

New Zealand

All about Pseudotachylite and Felsite Properties

Know all about Pseudotachylite and Felsite properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite belongs to Metamorphic Rocks while Felsite belongs to Igneous Rocks.Texture of Pseudotachylite is Quench whereas that of Felsite is Arborescent Patterned, Vitreous. Pseudotachylite appears Dull and Soft and Felsite appears Layered, Banded, Veined and Shiny. The luster of Pseudotachylite and Felsite is vitreous. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Felsite are mirror, jewelry.