Pseudotachylite

Gossan

Pseudotachylite and Gossan

Pseudotachylite

Gossan

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Definition

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

Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.

History

Origin

USA

Indonesia

Discoverer

Unknown

Cornish Gossen

Etymology

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

From Cornish gossen from gos, blood from Old Cornish guit

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Quench

Rough, Sandy

Color

Black, Brown, Green, Grey, Pink, White

Brown, Brown- Black, Gold, Green, Rust

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Dull and Banded

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Countertops, Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

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

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

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Gemstone

Cemetery Markers, Commemorative Tablets, Gemstone

Types

Cataclastic rock

Translocated gossan and Leakage gossan

Features

Host Rock for Lead

Clasts are smooth to touch, Easily splits into thin plates

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.

Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.

Composition

Mineral Content

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon

Compound Content

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

74-5

1 7

👆🏻

Grain Size

Very fine-grained

Fine to Medium Grained

Fracture

Uneven

Conchoidal

Streak

Light to dark brown

White to Grey

Porosity

Less Porous

Highly Porous

Luster

Vitreous

Metallic

Compressive Strength

60.00 N/mm²-

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.46-2.862.0

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 K0.24 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

South Korea

China, India, Indonesia, Russia, Singapore, South Korea

Africa

Western Africa

Cape Verde, Ethiopia, Ghana, South Africa, Western Africa

Europe

Great Britain, Switzerland

Albania, France, Germany, Great Britain, United Kingdom

Others

Deposits in Western Continents

North America

Canada, USA

South America

Brazil, Colombia, Ecuador

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New South Wales, South Australia, Western Australia

All about Pseudotachylite and Gossan Properties

Know all about Pseudotachylite and Gossan properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite and Gossan belong to Metamorphic Rocks.Texture of Pseudotachylite is Quench whereas that of Gossan is Rough, Sandy. Pseudotachylite appears Dull and Soft and Gossan appears Dull and Banded. The luster of Pseudotachylite is vitreous while that of Gossan is metallic. Pseudotachylite is available in black, brown, green, grey, pink, white colors whereas Gossan is available in brown, brown- black, gold, green, rust colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Gossan are cemetery markers, commemorative tablets, gemstone.