Chalk

Obsidian

Chalk vs Obsidian

Chalk

Obsidian

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1 Definition

1.1 Definition

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

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth

1.2 History

1.2.1 Origin

Unknown

Ethiopia

1.2.2 Discoverer

Unknown

Obsius

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 Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

1.4 Class

Sedimentary Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Clastic or Non-Clastic

Glassy

2.2 Color

Grey, White, Yellow

Black, Blue, Brown, Green, Orange, Red, Tan, 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

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

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

Garden Decoration

3.1.3 Other Architectural Uses

Powder

Not Yet Used

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

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Jewellery

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

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Not Available

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

4.2 Features

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

Blocks negativity, Helps to protect against depression

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Used

Not Yet 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.

When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.

5.2 Composition

5.2.1 Mineral Content

Calcite, Clay, Clay Minerals, Quartz, Sand

Not Available

5.2.2 Compound Content

Ca, NaCl, CaO

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

15-5.5

1 7

6.1.2 Grain Size

Very fine-grained

Not Applicable

6.1.3 Fracture

Not Available

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

Very Less Porous

6.1.6 Luster

Dull

Vitreous

6.1.7 Compressive Strength

NA0.15 N/mm²

0.15 450

6.1.8 Cleavage

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.3-2.42.6-2.7

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.49-2.50 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.90 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

1.4.2 Resistance

Heat Resistant

Heat Resistant, Impact Resistant

2 Reserves

2.1 Deposits in Eastern Continents

2.1.1 Asia

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

Afghanistan, Indonesia, Japan, Russia

2.1.2 Africa

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

Kenya

2.1.3 Europe

England, France, Germany, Spain, United Kingdom

Greece, Hungary, Iceland, Italy, Turkey

2.1.4 Others

Not Yet Found

2.2 Deposits in Western Continents

2.2.1 North America

Canada, USA

Canada, Mexico, USA

2.2.2 South America

Colombia

Argentina, Chile, Ecuador, Peru

2.3 Deposits in Oceania Continent

2.3.1 Australia

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

New Zealand

Chalk vs Obsidian Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Chalk and Obsidian Reserves. Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers. Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Chalk vs Obsidian information and Chalk vs Obsidian characteristics in the upcoming sections.

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Chalk vs Obsidian Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Chalk vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chalk and Properties of Obsidian. Learn more about Chalk vs Obsidian in the next section. The interior uses of Chalk include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Chalk and Obsidian, they have various applications in construction industry. The uses of Chalk in construction industry include 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 and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.

More about Chalk and Obsidian

Here you can know more about Chalk and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chalk and Obsidian consists of mineral content and compound content. The mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand and mineral content of Obsidian is not available. You can also check out the list of all Sedimentary Rocks. When we have to compare Chalk vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Chalk is available in grey, white, yellow colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Chalk is Soft and that of Obsidian is Shiny. Properties of rock is another aspect for Chalk vs Obsidian. The hardness of Chalk is 1 and that of Obsidian is 5-5.5. The types of Chalk are Not Available whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chalk and Obsidian is white. The specific heat capacity of Chalk is 0.90 kJ/Kg K and that of Obsidian is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Chalk is heat resistant whereas Obsidian is heat resistant, impact resistant.