Blueschist

Pseudotachylite

Blueschist and Pseudotachylite

Blueschist

Pseudotachylite

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1 Definition

1.1 Definition

Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature

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

Edgar Bailey

Unknown

1.3 Etymology

From French schiste, Greek skhistos i.e. split

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

1.4 Class

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

1.6 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Foliated

Quench

2.2 Color

Blue, Bluish - Grey, Purple, Shades of Blue

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

Dull and Banded

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration

3.1.3 Other Architectural Uses

Not Yet Used

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones

Creating Artwork, Gemstone

4 Types

4.1 Types

Not Available

4.2 Features

Has High structural resistance against erosion and climate, Very fine grained rock

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

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

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

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

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

3.5-47

1 7

6.1.2 Grain Size

Fine to Medium Grained

Very fine-grained

6.1.3 Fracture

Conchoidal

Uneven

6.1.4 Streak

White to Grey

Light to dark brown

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Dull

Vitreous

6.1.7 Compressive Strength

NA60.00 N/mm²

0.15 450

6.1.8 Cleavage

Slaty

Irregular

6.1.9 Toughness

1.5

Not Available

6.1.10 Specific Gravity

3-3.22.46-2.86

0 8.4

6.1.11 Transparency

Opaque

Transparent to Translucent

6.1.12 Density

2.8-2.9 g/cm³2.7-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Impact Resistant, Pressure Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Japan, Turkey

South Korea

7.1.2 Africa

Egypt, Ethiopia, South Africa

Western Africa

7.1.3 Europe

France, Greece, Iceland

Great Britain, Switzerland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

USA

Not Yet Found

7.2.2 South America

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

Central Australia, Western Australia

All about Blueschist and Pseudotachylite Properties

Know all about Blueschist and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Blueschist and Pseudotachylite belong to Metamorphic Rocks.Texture of Blueschist is Foliated whereas that of Pseudotachylite is Quench. Blueschist appears Dull and Banded and Pseudotachylite appears Dull and Soft. The luster of Blueschist is dull while that of Pseudotachylite is vitreous. Blueschist is available in blue, bluish - grey, purple, shades of blue colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Blueschist are cemetery markers, commemorative tablets, creating artwork, curling, tombstones and that of Pseudotachylite are creating artwork, gemstone.