Rhyodacite

Pseudotachylite

Rhyodacite and Pseudotachylite

Rhyodacite

Pseudotachylite

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1 Definition

1.1 Definition

Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite

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

USA

1.2.2 Discoverer

Unknown

1.3 Etymology

Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite

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

Earthy

Quench

2.2 Color

Black to Grey, Dark Greenish - Grey

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

Skeletal

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

As Building 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

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork, Gemstone

4 Types

4.1 Types

Not Available

4.2 Features

Available in Lots of Colors and Patterns

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

Rhyodacite 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

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

5.2.2 Compound Content

Ca, Fe, Potassium Oxide, NA, Potassium, Silicon Dioxide

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal 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, Coastal Erosion, Glacier Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5.5-67

1 7

6.1.2 Grain Size

Fine Grained

Very fine-grained

6.1.3 Fracture

Conchoidal

Uneven

6.1.4 Streak

Black

Light to dark brown

6.1.5 Porosity

Less Porous

6.1.6 Luster

Greasy to Dull

Vitreous

6.1.7 Compressive Strength

200.50 N/mm²60.00 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Irregular

6.1.9 Toughness

2.1

Not Available

6.1.10 Specific Gravity

2.34-2.402.46-2.86

0 8.4

6.1.11 Transparency

Opaque

Transparent to Translucent

6.1.12 Density

Not Available2.7-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

1.12 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

South Korea

7.1.2 Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Western Africa

7.1.3 Europe

Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland

Great Britain, Switzerland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Not Yet Found

7.2.2 South America

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

Central Australia, Western Australia

All about Rhyodacite and Pseudotachylite Properties

Know all about Rhyodacite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Rhyodacite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Rhyodacite is Earthy whereas that of Pseudotachylite is Quench. Rhyodacite appears Skeletal and Pseudotachylite appears Dull and Soft. The luster of Rhyodacite is greasy to dull while that of Pseudotachylite is vitreous. Rhyodacite is available in black to grey, dark greenish - grey colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Rhyodacite are cemetery markers, creating artwork and that of Pseudotachylite are creating artwork, gemstone.