Adakite and Dacite

Adakite

Dacite

Definition

Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs

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

History

Origin

Adak, Aleutian Islands

Romania and Moldova, Europe

Discoverer

Defant and Drummond

Unknown

Etymology

From Adak, Aleutian Islands

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Porphyritic

Aphanitic to Porphyritic

Color

Black, Brown, Light to Dark Grey

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

Maintenance

Less

Durability

Durable

Water Resistant

Scratch Resistant

Stain Resistant

Wind Resistant

Yes

Acid Resistant

Yes

Appearance

Dull and Soft

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Office Buildings

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Whetstones

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

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

Medical Industry

Not Yet Used

Antiquity Uses

Monuments, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

Commemorative Tablets, Pottery, Used in aquariums

Commemorative Tablets, Creating Artwork

Types

Not Available

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock

Host Rock for Lead, Is one of the oldest rock

Archaeological Significance

Monuments

Used

Not Yet Used

Famous Monuments

Data Not Available

Not Applicable

Sculpture

Used

Not Yet Used

Famous Sculptures

Data Not Available

Not Applicable

Pictographs

Used

Petroglyphs

Used

Figurines

Used

Not Yet Used

Fossils

Absent

Formation

Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.

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.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

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

Compound Content

Aluminium Oxide, MgO, Silicon Dioxide

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

Transformation

Metamorphism

Yes

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

Yes

Types of Weathering

Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

Yes

Types of Erosion

Coastal Erosion, Sea Erosion, Water Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

3-4

2-2.25

Grain Size

Fine to Medium Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

Bluish Black

White

Porosity

Less Porous

Luster

Grainy, Pearly and Vitreous

Subvitreous to Dull

Cleavage

Not Available

Perfect

Toughness

Not Available

Specific Gravity

Not Available

2.86-2.87

Transparency

Opaque

Translucent

Density

Not Available

2.77-2.771 g/cm³

Thermal Properties

Specific Heat Capacity

Not Available

0.92 kJ/Kg K

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Not Yet Found

Africa

Ethiopia, Somalia, South Africa

Not Yet Found

Europe

Iceland

France, Greece, Romania, Scotland, Spain

Others

Not Yet Found

Deposits in Western Continents

North America

Canada, USA

USA

South America

Brazil

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

Deposits in Oceania Continent

Australia

Not Yet Found

New Zealand, South Australia, Western Australia

Summary >>

<< Reserves

All about Adakite and Dacite Properties

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