Pseudotachylite

Dacite

Pseudotachylite and Dacite

Pseudotachylite

Dacite

Add ⊕

1 Definition

1.1 Definition

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

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

1.2 History

1.2.1 Origin

USA

Romania and Moldova, Europe

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

1.4 Class

Metamorphic Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Quench

Aphanitic to Porphyritic

2.2 Color

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

Bluish - Grey, Brown, Grey, Light to Dark Grey

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

Vesicular

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

As Building Stone, 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

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

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

Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Not Available

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

4.2 Features

Host Rock for Lead

Host Rock for Lead, 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

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.

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

5.2 Composition

5.2.1 Mineral Content

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

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

5.2.2 Compound Content

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Cataclastic 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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

72-2.25

1 7

6.1.2 Grain Size

Very fine-grained

Medium to Fine Coarse Grained

6.1.3 Fracture

Uneven

Conchoidal

6.1.4 Streak

Light to dark brown

White

6.1.5 Porosity

Less Porous

6.1.6 Luster

Vitreous

Subvitreous to Dull

6.1.7 Compressive Strength

60.00 N/mm²NA

0.15 450

6.1.8 Cleavage

Irregular

Perfect

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.46-2.862.86-2.87

0 8.4

6.1.11 Transparency

Transparent to Translucent

Translucent

6.1.12 Density

2.7-2.9 g/cm³2.77-2.771 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, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

South Korea

Not Yet Found

7.1.2 Africa

Western Africa

Not Yet Found

7.1.3 Europe

Great Britain, Switzerland

France, Greece, Romania, Scotland, Spain

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Not Yet Found

USA

7.2.2 South America

Not Yet Found

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

7.3 Deposits in Oceania Continent

7.3.1 Australia

Central Australia, Western Australia

New Zealand, South Australia, Western Australia

All about Pseudotachylite and Dacite Properties

Know all about Pseudotachylite and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite belongs to Metamorphic Rocks while Dacite belongs to Igneous Rocks.Texture of Pseudotachylite is Quench whereas that of Dacite is Aphanitic to Porphyritic. Pseudotachylite appears Dull and Soft and Dacite appears Vesicular. The luster of Pseudotachylite is vitreous while that of Dacite is subvitreous to dull. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Dacite are commemorative tablets, creating artwork.