Obsidian

Soapstone

Obsidian and Soapstone

Obsidian

Soapstone

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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

It is a metamorphic magnesium rich rock because it is composed of the mineral talc

1.2 History

1.2.1 Origin

Ethiopia

USA

1.2.2 Discoverer

Obsius

Unknown

1.3 Etymology

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

From 17th century, because of its greasy feel and use like a soap

1.4 Class

Igneous Rocks

Metamorphic 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

Polished

2.2 Color

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

Black, Black to Grey, Green, Grey

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

Shiny

Dull, Banded and Foilated

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Bathrooms, Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration

As Facing Stone, Garden Decoration

3.1.3 Other Architectural Uses

Not Yet Used

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Manufacture of Magnesium and Dolomite Refractories

3.2.2 Medical Industry

Surgery

Taken as a Supplement for Calcium or Magnesium

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts, Jewellery, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)

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

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire

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

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.

Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.

5.2 Composition

5.2.1 Mineral Content

Not Available

Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz

5.2.2 Compound Content

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

CaO, Mg, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.51

1 7

6.1.2 Grain Size

Not Applicable

Fine Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

Black

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Vitreous

Greasy

6.1.7 Compressive Strength

0.15 N/mm²225.00 N/mm²

0.15 450

6.1.8 Cleavage

Non-Existent

Perfect

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.72.86

0 8.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³2.8-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand

7.1.2 Africa

Kenya

Egypt, Ethiopia, Ghana, South Africa, Western Africa

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, 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

Central Australia, New Zealand, Queensland

All about Obsidian and Soapstone Properties

Know all about Obsidian and Soapstone properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Soapstone belongs to Metamorphic Rocks.Texture of Obsidian is Glassy whereas that of Soapstone is Polished. Obsidian appears Shiny and Soapstone appears Dull, Banded and Foilated. The luster of Obsidian is vitreous while that of Soapstone is greasy. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Soapstone is available in black, black to grey, green, grey colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Soapstone are cemetery markers, creating artwork, gemstone, jewelry, manufacture of soap, solvents, dyes, plastics and fibres, production of lime, source of magnesia (mgo).