Gneiss

Pseudotachylite

Gneiss vs Pseudotachylite

Gneiss

Pseudotachylite

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1 Definition

1.1 Definition

Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks

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 the Middle High German verb gneist (to spark; so called because the rock glitters)

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

1.4 Class

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

1.6 Other Categories

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Banded, Foliated, Platy

Quench

2.2 Color

Black, Brown, Pink, Red, White

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

Foliated

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Countertops, Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

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

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, Jewelry, Tombstones, Used in aquariums

Creating Artwork, Gemstone

4 Types

4.1 Types

Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.

Not Available

4.2 Features

Generally rough to touch, Is one of the oldest rock

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Konark Sun Temple in India, Washington Monument, US

Data Not Available

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.

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

Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

5.2.2 Compound Content

Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, 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

Impact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Sea Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

1 7

6.1.2 Grain Size

Medium to Coarse Grained

Very fine-grained

6.1.3 Fracture

Irregular

Uneven

6.1.4 Streak

White

Light to dark brown

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Dull

Vitreous

6.1.7 Compressive Strength

125.00 N/mm²60.00 N/mm²

0.15 450

6.1.8 Cleavage

Poor

Irregular

6.1.9 Toughness

1.2

Not Available

6.1.10 Specific Gravity

2.5-2.72.46-2.86

0 8.4

6.1.11 Transparency

Translucent to Opaque

Transparent to Translucent

6.1.12 Density

2.6-2.9 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

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia

South Korea

7.1.2 Africa

Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo

Western Africa

7.1.3 Europe

Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom

Great Britain, Switzerland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Costa Rica, Cuba, Mexico, Panama, USA

Not Yet Found

7.2.2 South America

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

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand, Queensland, Victoria

Central Australia, Western Australia

Gneiss vs Pseudotachylite Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Gneiss and Pseudotachylite Reserves. Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks. Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Gneiss vs Pseudotachylite information and Gneiss vs Pseudotachylite characteristics in the upcoming sections.

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Gneiss vs Pseudotachylite Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Gneiss vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Pseudotachylite. Learn more about Gneiss vs Pseudotachylite in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Gneiss and Pseudotachylite, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.

More about Gneiss and Pseudotachylite

Here you can know more about Gneiss and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Pseudotachylite consists of mineral content and compound content. The mineral content of Gneiss includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Gneiss is available in black, brown, pink, red, white colors whereas, Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Gneiss is Foliated and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Gneiss vs Pseudotachylite. Hardness of Gneiss and Pseudotachylite is 7. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Pseudotachylite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss is white while that of Pseudotachylite is light to dark brown. The specific heat capacity of Gneiss is Not Available and that of Pseudotachylite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Gneiss is heat resistant, pressure resistant, scratch resistant, wear resistant whereas Pseudotachylite is heat resistant.