Chalk

Argillite

Chalk and Argillite

Chalk

Argillite

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Definition

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

Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate

History

Origin

Discoverer

Unknown

Etymology

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

From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite

Class

Sedimentary Rocks

Sub-Class

Durable Rock, Soft Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic or Non-Clastic

Clastic, Polished

Color

Grey, White, Yellow

Dark Grey to Black, Pink, Red, White

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

As Building Stone, Garden Decoration, Office Buildings

Other Architectural Uses

Powder

Curbing, 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

Used for flooring, stair treads, borders and window sills.

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

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

Fire resistant, Used to manufracture paperweights and bookends

Types

Chalk Marl and Marl

Metamorphic rock

Features

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

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.

An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.

Composition

Mineral Content

Calcite, Clay, Clay Minerals, Quartz, Sand

Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz

Compound Content

Ca, NaCl, CaO

Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

12-3

1 7

👆🏻

Grain Size

Very fine-grained

Fine Grained

Fracture

Conchoidal to Uneven

Streak

White

White to Grey

Porosity

Highly Porous

Luster

Dull

Waxy and Dull

Compressive Strength

5.00 N/mm²-

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.6

Specific Gravity

2.3-2.42.56-2.68

0 8.4

👆🏻

Transparency

Opaque

Density

2.49-2.50 g/cm³2.54-2.66 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.90 kJ/Kg K0.87 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Bangladesh, China, India, Russia

Africa

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

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Europe

England, France, Germany, Spain, United Kingdom

Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland

Others

Deposits in Western Continents

North America

Canada, USA

USA

South America

Colombia

Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula

New South Wales, New Zealand, Queensland, Victoria, Western Australia

All about Chalk and Argillite Properties

Know all about Chalk and Argillite properties here. All properties of rocks are important as they define the type of rock and its application. Chalk and Argillite belong to Sedimentary Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Argillite is Clastic, Polished. Chalk appears Soft and Argillite appears Rough and Dull. The luster of Chalk is dull while that of Argillite is waxy and dull. Chalk is available in grey, white, yellow colors whereas Argillite is available in dark grey to black, pink, red, white 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 Argillite are fire resistant, used to manufracture paperweights and bookends.