Chalk

Arkose

Chalk and Arkose

Chalk

Arkose

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Definition

Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers

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

History

Origin

France

Discoverer

Unknown

Alexandre Brongniart

Etymology

From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone

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

Class

Sedimentary Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Clastic or Non-Clastic

Clastic

Color

Grey, White, Yellow

Reddish Brown

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Soft

Rough and Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

Paving Stone, Office Buildings

Other Architectural Uses

Powder

Whetstones

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium

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

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper

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

Types

Chalk Marl and Marl

Arkose

Features

Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Formation

Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.

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.

Composition

Mineral Content

Calcite, Clay, Clay Minerals, Quartz, Sand

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

Compound Content

Ca, NaCl, CaO

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

16-7

1 7

👆🏻

Grain Size

Very fine-grained

Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Luster

Dull

Compressive Strength

5.00 N/mm²80.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.3-2.40

0 8.4

👆🏻

Transparency

Opaque

Density

2.49-2.50 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.90 kJ/Kg K0.78 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

Africa

Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe

Namibia, Nigeria, South Africa

Europe

England, France, Germany, Spain, United Kingdom

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

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

South America

Colombia

Brazil

Deposits in Oceania Continent

Australia

Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula

New South Wales, New Zealand

All about Chalk and Arkose Properties

Know all about Chalk and Arkose properties here. All properties of rocks are important as they define the type of rock and its application. Chalk and Arkose belong to Sedimentary Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Arkose is Clastic. Chalk appears Soft and Arkose appears Rough and Dull. The luster of Chalk and Arkose is dull. Chalk is available in grey, white, yellow colors whereas Arkose is available in reddish brown colors. The commercial uses of Chalk are alumina refineries, creating artwork, drawing on blackboards, gymnasts, athletes and mountain climbers use for grip, in aquifers, paper industry, production of lime, raw material for manufacture of quicklime, slaked lime, soil conditioner, whiting, whiting material in toothpaste, paint and paper and that of Arkose are in aquifers, soil conditioner, source of magnesia (mgo), tombstones.