Dacite

Andesite

Dacite and Andesite

Dacite

Andesite

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Definition

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

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

History

Origin

Romania and Moldova, Europe

North America

Discoverer

Unknown

Theodor von Gümbel

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 Andes mountains, where it is found in abundance

Class

Igneous Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Color

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

Bluish - Grey, Grey, Pink, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

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

Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

Office Buildings, Roof Tiles

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Cobblestones, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Icelandite

Features

Host Rock for Lead, Is one of the oldest rock

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

Archaeological Significance

Monuments

Famous Monuments

Middle of the Earth in Ecuador

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

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

Composition

Mineral Content

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

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

Compound Content

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

Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

2-2.257

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Very fine-grained

Fracture

Conchoidal

Uneven

Streak

White

Porosity

Less Porous

Luster

Subvitreous to Dull

Vitreous

Compressive Strength

70.00 N/mm²225.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.1

Specific Gravity

2.86-2.872.5-2.8

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.77-2.771 g/cm³2.11-2.36 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K2.39 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Indonesia, Japan, Nepal, South Korea

Africa

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

Europe

France, Greece, Romania, Scotland, Spain

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

Others

Deposits in Western Continents

North America

USA

Mexico, USA

South America

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

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

New South Wales, New Zealand, Western Australia

All about Dacite and Andesite Properties

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