Pegmatite

Obsidian

Pegmatite and Obsidian

Pegmatite

Obsidian

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1 Definition

1.1 Definition

Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals

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

R. J. Hauy

Obsius

1.3 Etymology

From Greek pegma, pegmat which means- thing joined together + -ite

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

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Plutonic

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Pegmatitic

Glassy

2.2 Color

Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, 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

Layered, Banded, Veined and Shiny

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, As Facing Stone, Paving Stone

Garden Decoration

3.1.3 Other Architectural Uses

Curbing

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

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

4.2 Features

Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz

Blocks negativity, Helps to protect against depression

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.

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

Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz

Not Available

5.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide

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

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

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

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

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

75-5.5

1 7

6.1.2 Grain Size

Medium to Coarse Grained

Not Applicable

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

Very Less Porous

6.1.6 Luster

Grainy, Pearly and Vitreous

Vitreous

6.1.7 Compressive Strength

178.54 N/mm²0.15 N/mm²

0.15 450

6.1.8 Cleavage

Perfect

Non-Existent

6.1.9 Toughness

2.1

Not Available

6.1.10 Specific Gravity

2.6-2.632.6-2.7

0 8.4

6.1.11 Transparency

Translucent to Opaque

Translucent

6.1.12 Density

2.6-2.65 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

South Africa

Kenya

7.1.3 Europe

Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada

Canada, Mexico, USA

7.2.2 South America

Brazil

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, Queensland, South Australia, Western Australia

New Zealand

All about Pegmatite and Obsidian Properties

Know all about Pegmatite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Pegmatite and Obsidian belong to Igneous Rocks.Texture of Pegmatite is Pegmatitic whereas that of Obsidian is Glassy. Pegmatite appears Layered, Banded, Veined and Shiny and Obsidian appears Shiny. The luster of Pegmatite is grainy, pearly and vitreous while that of Obsidian is vitreous. Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz and that of Obsidian are creating artwork, mirror, used in aquariums.