Rhyolite

Obsidian

Rhyolite and Obsidian

Rhyolite

Obsidian

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1 Definition

1.1 Definition

Rhyolite is a fine-grained igneous rock which is rich in silica

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

North America

Ethiopia

1.2.2 Discoverer

Ferdinand von Richthofen

Obsius

1.3 Etymology

From German Rhyolit, from Greek rhuax lava stream + lithos stone

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

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Aphanitic, Glassy, Porphyritic

Glassy

2.2 Color

Grey, White, Light Black

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

Banded

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, As Facing Stone, Paving Stone, Office Buildings

Garden Decoration

3.1.3 Other Architectural Uses

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

Gemstone, Laboratory bench tops, Jewelry

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.

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

4.2 Features

Acidic in nature, Available in lots of colors

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

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.

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

Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz

Not Available

5.2.2 Compound Content

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium

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, 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, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-75-5.5

1 7

6.1.2 Grain Size

Large and Coarse Grained

Not Applicable

6.1.3 Fracture

Sub-conchoidal

Conchoidal

6.1.4 Streak

Colorless

White

6.1.5 Porosity

Highly Porous

Very Less Porous

6.1.6 Luster

Earthy

Vitreous

6.1.7 Compressive Strength

140.00 N/mm²0.15 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.65-2.672.6-2.7

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.4-2.6 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, Wear Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Kenya

7.1.3 Europe

Germany, Iceland, Ireland, Italy, Spain

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Mexico, USA

7.2.2 South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, Queensland, Western Australia

New Zealand

All about Rhyolite and Obsidian Properties

Know all about Rhyolite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Rhyolite and Obsidian belong to Igneous Rocks.Texture of Rhyolite is Aphanitic, Glassy, Porphyritic whereas that of Obsidian is Glassy. Rhyolite appears Banded and Obsidian appears Shiny. The luster of Rhyolite is earthy while that of Obsidian is vitreous. Rhyolite is available in grey, white, light black colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Rhyolite are gemstone, laboratory bench tops, jewelry and that of Obsidian are creating artwork, mirror, used in aquariums.