Chalk

Picrite

Chalk and Picrite

Chalk

Picrite

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1 Definition

1.1 Definition

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

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

1.2 History

1.2.1 Origin

Unknown

Hawaii Islands

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From Greek pikros bitter + -ite, 19th century

1.4 Class

Sedimentary Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Clastic or Non-Clastic

Earthy, Rough

2.2 Color

Grey, White, Yellow

Black, Brown, Colourless, Green, Grey, Pink, White, Yellow

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Soft

Rough and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

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

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

3.1.3 Other Architectural Uses

Powder

Curbing

3.2 Industry

3.2.1 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

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 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

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

4 Types

4.1 Types

Not Available

Oceanite

4.2 Features

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

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Used

4.4 Fossils

Present

Absent

5 Formation

5.1 Formation

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

Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

5.2 Composition

5.2.1 Mineral Content

Calcite, Clay, Clay Minerals, Quartz, Sand

Biotite, Olivine, Plagioclase, Pyrrhotite

5.2.2 Compound Content

Ca, NaCl, CaO

Al, CaO, Carbon Dioxide, Mg, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

16.8

1 7

6.1.2 Grain Size

Very fine-grained

Fine Grained

6.1.3 Fracture

Not Available

Uneven

6.1.4 Streak

White

White, Greenish White or Grey

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Dull

Subvitreous to Dull

6.1.7 Compressive Strength

NA189.00 N/mm²

0.15 450

6.1.8 Cleavage

Non-Existent

Imperfect

6.1.9 Toughness

2.1

6.1.10 Specific Gravity

2.3-2.42.75-2.92

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

2.49-2.50 g/cm³1.5-2.5 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.90 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

India, Russia

7.1.2 Africa

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

South Africa

7.1.3 Europe

England, France, Germany, Spain, United Kingdom

Iceland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

7.2.2 South America

Colombia

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula

Not Yet Found

All about Chalk and Picrite Properties

Know all about Chalk and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Chalk belongs to Sedimentary Rocks while Picrite belongs to Igneous Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Picrite is Earthy, Rough. Chalk appears Soft and Picrite appears Rough and Shiny. The luster of Chalk is dull while that of Picrite is subvitreous to dull. Chalk is available in grey, white, yellow colors whereas Picrite is available in black, brown, colourless, green, grey, pink, white, yellow 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 Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).