Andesite

Dacite

Andesite and Dacite

Andesite

Dacite

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1 Definition

1.1 Definition

Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava

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

1.2 History

1.2.1 Origin

North America

Romania and Moldova, Europe

1.2.2 Discoverer

Unknown

1.3 Etymology

From Andes mountains, where it is found in abundance

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

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic to Porphyritic

2.2 Color

Bluish - Grey, Grey, Pink, Yellow

Bluish - Grey, Brown, Grey, Light to Dark 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

Dull and Soft

Vesicular

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

Office Buildings, Roof Tiles

As Building Stone, Paving Stone, Garden Decoration

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Cobblestones, Construction Aggregate, for Road Aggregate

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Icelandite

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

4.2 Features

Generally rough to touch, High silica content, Is one of the oldest rock

Host Rock for Lead, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Middle of the Earth in Ecuador

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

Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.

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.

5.2 Composition

5.2.1 Mineral Content

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

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

5.2.2 Compound Content

Silicon Dioxide

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

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

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

72-2.25

1 7

6.1.2 Grain Size

Very fine-grained

Medium to Fine Coarse Grained

6.1.3 Fracture

Uneven

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

6.1.6 Luster

Vitreous

Subvitreous to Dull

6.1.7 Compressive Strength

225.00 N/mm²NA

0.15 450

6.1.8 Cleavage

Not Available

Perfect

6.1.9 Toughness

1.1

Not Available

6.1.10 Specific Gravity

2.5-2.82.86-2.87

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.11-2.36 g/cm³2.77-2.771 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

2.39 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Indonesia, Japan, Nepal, South Korea

Not Yet Found

7.1.2 Africa

Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania

Not Yet Found

7.1.3 Europe

Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom

France, Greece, Romania, Scotland, Spain

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Mexico, USA

USA

7.2.2 South America

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

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand, Western Australia

New Zealand, South Australia, Western Australia

All about Andesite and Dacite Properties

Know all about Andesite and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Andesite and Dacite belong to Igneous Rocks.Texture of Andesite is Aphanitic to Porphyritic whereas that of Dacite is Aphanitic to Porphyritic. Andesite appears Dull and Soft and Dacite appears Vesicular. The luster of Andesite is vitreous while that of Dacite is subvitreous to dull. Andesite is available in bluish - grey, grey, pink, yellow colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Andesite and Dacite are commemorative tablets, creating artwork.