Pseudotachylite

Migmatite

Pseudotachylite and Migmatite

Pseudotachylite

Migmatite

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Definition

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

Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components

History

Origin

USA

Southern Alps, France

Discoverer

Unknown

Jakob Sederholm

Etymology

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

From the Greek word migma which means a mixture

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Quench

Foliated

Color

Black, Brown, Green, Grey, Pink, White

Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Countertops, Flooring, Kitchens

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

As Building Stone, As Facing Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Gemstone

Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends

Types

Cataclastic rock

Diatexites and Metatexites

Features

Host Rock for Lead

Generally rough to touch, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.

Composition

Mineral Content

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

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

Compound Content

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

75.5-6.5

1 7

👆🏻

Grain Size

Very fine-grained

Medium to Fine Coarse Grained

Fracture

Uneven

Irregular

Streak

Light to dark brown

White

Porosity

Less Porous

Very Less Porous

Luster

Vitreous

Dull to Pearly to Subvitreous

Compressive Strength

60.00 N/mm²120.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.2

Specific Gravity

2.46-2.862.65-2.75

0 8.4

👆🏻

Transparency

Transparent to Translucent

Opaque

Density

2.7-2.9 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

South Korea

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

Africa

Western Africa

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

Europe

Great Britain, Switzerland

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

Others

Deposits in Western Continents

North America

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

South America

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

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New South Wales, New Zealand, Queensland, Victoria

All about Pseudotachylite and Migmatite Properties

Know all about Pseudotachylite and Migmatite properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite and Migmatite belong to Metamorphic Rocks.Texture of Pseudotachylite is Quench whereas that of Migmatite is Foliated. Pseudotachylite appears Dull and Soft and Migmatite appears Dull, Banded and Foilated. The luster of Pseudotachylite is vitreous while that of Migmatite is dull to pearly to subvitreous. Pseudotachylite is available in black, brown, green, grey, pink, white colors whereas Migmatite is available in black, bluish - grey, brown, brown- black, dark greenish - grey, dark grey to black colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Migmatite are cemetery markers, jewelry, tombstones, used to manufracture paperweights and bookends.