Obsidian

Chalk

Obsidian and Chalk

Obsidian

Chalk

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1 Definition

1.1 Definition

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

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

1.2 History

1.2.1 Origin

Ethiopia

Unknown

1.2.2 Discoverer

Obsius

Unknown

1.3 Etymology

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

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

1.4 Class

Igneous Rocks

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy

Clastic or Non-Clastic

2.2 Color

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

Grey, White, Yellow

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

59% Sedimentary Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

62% Sedimentary Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

43% Sedimentary Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

38% Sedimentary Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

22% Sedimentary Rocks Rocks have it !

2.5 Appearance

Shiny

Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration

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

3.1.3 Other Architectural Uses

Not Yet Used

Powder

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

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

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

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

4 Types

4.1 Types

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

Not Available

4.2 Features

Blocks negativity, Helps to protect against depression

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

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

Present

5 Formation

5.1 Formation

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.

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

5.2 Composition

5.2.1 Mineral Content

Not Available

Calcite, Clay, Clay Minerals, Quartz, Sand

5.2.2 Compound Content

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

Ca, NaCl, CaO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

19% Sedimentary Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

78% Sedimentary Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

86% Sedimentary Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.5

6.1.2 Grain Size

Not Applicable

Very fine-grained

6.1.3 Fracture

Conchoidal

Not Available

6.1.4 Streak

White

6.1.5 Porosity

Very Less Porous

Highly Porous

6.1.6 Luster

Vitreous

Dull

6.1.7 Compressive Strength

What Is Flint

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▼

0.15 N/mm²

Rank: 33 (Overall)▶

Not Available

Rank: N/A (Overall)▶

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What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.7

2.3-2.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³

2.49-2.50 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

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▶

▼

0.92 kJ/Kg K

Rank: 10 (Overall)▶

0.90 kJ/Kg K

Rank: 12 (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

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

7.1.2 Africa

Kenya

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

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

England, France, Germany, Spain, United Kingdom

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Colombia

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

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

All about Obsidian and Chalk Properties

Know all about Obsidian and Chalk properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Chalk belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Chalk is Clastic or Non-Clastic. Obsidian appears Shiny and Chalk appears Soft. The luster of Obsidian is vitreous while that of Chalk is dull. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Chalk is available in grey, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that 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.