Dacite

Obsidian

Dacite and Obsidian

Dacite

Obsidian

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1 Definition

1.1 Definition

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

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

Romania and Moldova, Europe

Ethiopia

1.2.2 Discoverer

Unknown

Obsius

1.3 Etymology

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

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

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Aphanitic to Porphyritic

Glassy

2.2 Color

Bluish - Grey, Brown, Grey, Light to Dark Grey

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

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

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81% Igneous Rocks Rocks have it !

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81% Igneous Rocks Rocks have it !

2.4.2 Scratch Resistant

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86% Igneous Rocks Rocks have it !

✔ ✘

86% Igneous Rocks Rocks have it !

2.4.3 Stain Resistant

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66% Igneous Rocks Rocks have it !

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66% Igneous Rocks Rocks have it !

2.4.4 Wind Resistant

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49% Igneous Rocks Rocks have it !

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49% Igneous Rocks Rocks have it !

2.4.5 Acid Resistant

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48% Igneous Rocks Rocks have it !

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48% Igneous Rocks Rocks have it !

2.5 Appearance

Vesicular

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

Garden Decoration

3.1.3 Other Architectural Uses

Curbing

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, 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

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

Commemorative Tablets, Creating Artwork

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

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

4.2 Features

Host Rock for Lead, Is one of the oldest rock

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

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

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

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Not Available

5.2.2 Compound Content

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

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

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97% Igneous Rocks Rocks have it !

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97% Igneous Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

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99% Igneous Rocks Rocks have it !

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99% Igneous Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

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92% Igneous Rocks Rocks have it !

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92% Igneous Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

2-2.25

5-5.5

6.1.2 Grain Size

Medium to Fine 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

Subvitreous to Dull

Vitreous

6.1.7 Compressive Strength

What Is Flint

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Not Available

Rank: N/A (Overall)▶

0.15 N/mm²

Rank: 33 (Overall)▶

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What Is Obsidian

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175 (What Is Grani..)

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6.1.8 Cleavage

Perfect

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.86-2.87

2.6-2.7

6.1.11 Transparency

Translucent

6.1.12 Density

2.77-2.771 g/cm³

2.6 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)▶

0.92 kJ/Kg K

Rank: 10 (Overall)▶

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What Is Granulite

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1.09 (What Is Trave..)

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6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Not Yet Found

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

Not Yet Found

Kenya

7.1.3 Europe

France, Greece, Romania, Scotland, Spain

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

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, South Australia, Western Australia

New Zealand

All about Dacite and Obsidian Properties

Know all about Dacite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Dacite and Obsidian belong to Igneous Rocks.Texture of Dacite is Aphanitic to Porphyritic whereas that of Obsidian is Glassy. Dacite appears Vesicular and Obsidian appears Shiny. The luster of Dacite is subvitreous to dull while that of Obsidian is vitreous. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Dacite are commemorative tablets, creating artwork and that of Obsidian are creating artwork, mirror, used in aquariums.