Arkose

Pseudotachylite

Arkose and Pseudotachylite

Arkose

Pseudotachylite

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Definition

Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar

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

History

Origin

France

USA

Discoverer

Alexandre Brongniart

Unknown

Etymology

From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones

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

Class

Sedimentary Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Clastic

Quench

Color

Reddish Brown

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Dull

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

Paving Stone, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration

Other Architectural Uses

Whetstones

Curbing

Industry

Construction Industry

Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar

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

Medical Industry

Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts, Monuments

Other Uses

Commercial Uses

In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones

Creating Artwork, Gemstone

Types

Arkose

Cataclastic rock

Features

Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

Arkose rock forms from the weathering of feldspar-rich igneous or metamorphic rock, most commonly granitic rocks, which are primarily composed of quartz and feldspar.

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.

Composition

Mineral Content

Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

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, Wind Erosion

Properties

Physical Properties

Hardness

6-77

1 7

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Grain Size

Coarse Grained

Very fine-grained

Fracture

Conchoidal

Uneven

Streak

White

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Dull

Vitreous

Compressive Strength

80.00 N/mm²60.00 N/mm²

0.15 450

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Cleavage

Toughness

Specific Gravity

02.46-2.86

0 8.4

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Transparency

Opaque

Transparent to Translucent

Density

-9999 g/cm³2.7-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.78 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

South Korea

Africa

Namibia, Nigeria, South Africa

Western Africa

Europe

Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom

Great Britain, Switzerland

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

South America

Brazil

Deposits in Oceania Continent

Australia

New South Wales, New Zealand

Central Australia, Western Australia

All about Arkose and Pseudotachylite Properties

Know all about Arkose and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Arkose belongs to Sedimentary Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Arkose is Clastic whereas that of Pseudotachylite is Quench. Arkose appears Rough and Dull and Pseudotachylite appears Dull and Soft. The luster of Arkose is dull while that of Pseudotachylite is vitreous. Arkose is available in reddish brown colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Arkose are in aquifers, soil conditioner, source of magnesia (mgo), tombstones and that of Pseudotachylite are creating artwork, gemstone.