Felsite

Pseudotachylite

Felsite and Pseudotachylite

Felsite

Pseudotachylite

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1 Definition

1.1 Definition

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

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

1.2 History

1.2.1 Origin

Unknown

USA

1.2.2 Discoverer

Unknown

1.3 Etymology

From English feldspar and -ite

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

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Arborescent Patterned, Vitreous

Quench

2.2 Color

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

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

Layered, Banded, Veined and Shiny

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

Paving Stone, Garden Decoration

As Building Stone, As Facing Stone, Garden Decoration

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

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

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Mirror, Jewelry

Creating Artwork, Gemstone

4 Types

4.1 Types

Not Available

4.2 Features

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

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

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.

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.

5.2 Composition

5.2.1 Mineral Content

Feldspar, Iron Oxides

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

5.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Glacier Erosion, Water Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.57

1 7

6.1.2 Grain Size

Fine Grained

Very fine-grained

6.1.3 Fracture

Conchoidal

Uneven

6.1.4 Streak

White

Light to dark brown

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Vitreous

6.1.7 Compressive Strength

0.15 N/mm²60.00 N/mm²

0.15 450

6.1.8 Cleavage

Non-Existent

Irregular

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.72.46-2.86

0 8.4

6.1.11 Transparency

Translucent

Transparent to Translucent

6.1.12 Density

2.6 g/cm³2.7-2.9 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, Impact Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

South Korea

7.1.2 Africa

Kenya

Western Africa

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Great Britain, Switzerland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Not Yet Found

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

Central Australia, Western Australia

All about Felsite and Pseudotachylite Properties

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