Pseudotachylite

Dunite

Pseudotachylite and Dunite

Pseudotachylite

Dunite

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Definition

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

Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine

History

Origin

USA

New Zealand

Discoverer

Unknown

Ferdinand von Hochstetter

Etymology

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

From the name of Dun Mountain, New Zealand, + -ite1

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Quench

Phaneritic

Color

Black, Brown, Green, Grey, Pink, White

Dark Greenish - Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Rough and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone

Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds

Types

Cataclastic rock

Dunite

Features

Host Rock for Lead

Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, 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.

Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.

Composition

Mineral Content

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene

Compound Content

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Properties

Physical Properties

Hardness

73.5-4

1 7

👆🏻

Grain Size

Very fine-grained

Coarse Grained

Fracture

Uneven

Irregular

Streak

Light to dark brown

White

Porosity

Less Porous

Luster

Vitreous

Shiny

Compressive Strength

60.00 N/mm²107.55 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

Specific Gravity

2.46-2.863-3.01

0 8.4

👆🏻

Transparency

Transparent to Translucent

Translucent to Opaque

Density

2.7-2.9 g/cm³2.84-2.85 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K1.25 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

South Korea

China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey

Africa

Western Africa

Morocco, South Africa

Europe

Great Britain, Switzerland

Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland

Others

Deposits in Western Continents

North America

Canada, USA

South America

Argentina, Brazil, Colombia, Ecuador, Venezuela

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New Zealand, Western Australia

All about Pseudotachylite and Dunite Properties

Know all about Pseudotachylite and Dunite properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite belongs to Metamorphic Rocks while Dunite belongs to Igneous Rocks.Texture of Pseudotachylite is Quench whereas that of Dunite is Phaneritic. Pseudotachylite appears Dull and Soft and Dunite appears Rough and Shiny. The luster of Pseudotachylite is vitreous while that of Dunite is shiny. Pseudotachylite is available in black, brown, green, grey, pink, white colors whereas Dunite is available in dark greenish - grey colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Dunite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.