Dacite and Migmatite

Dacite

Migmatite

Definition

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

Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components

History

Origin

Romania and Moldova, Europe

Southern Alps, France

Discoverer

Unknown

Jakob Sederholm

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 the Greek word migma which means a mixture

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Not Applicable

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Foliated

Color

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

Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Wind Resistant

Acid Resistant

Appearance

Vesicular

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Countertops, Flooring, Kitchens

Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

As Building Stone, As Facing Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends

Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Diatexites and Metatexites

Features

Host Rock for Lead, Is one of the oldest rock

Generally rough to touch, Is one of the oldest rock

Archaeological Significance

Monuments

Not Yet Used

Famous Monuments

Not Applicable

Sculpture

Not Yet Used

Famous Sculptures

Not Applicable

Pictographs

Used

Petroglyphs

Used

Figurines

Not Yet Used

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.

Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.

Composition

Mineral Content

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

Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon

Compound Content

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

Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

Yes

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Weathering

Yes

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

Yes

Types of Erosion

Chemical Erosion

Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

2-2.25

5.5-6.5

Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Irregular

Streak

White

Porosity

Less Porous

Very Less Porous

Luster

Subvitreous to Dull

Dull to Pearly to Subvitreous

Cleavage

Perfect

Poor

Toughness

Not Available

1.2

Specific Gravity

2.86-2.87

2.65-2.75

Transparency

Translucent

Opaque

Density

2.77-2.771 g/cm³

Not Available

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K

Not Available

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

Not Yet Found

China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia

Africa

Not Yet Found

Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo

Europe

France, Greece, Romania, Scotland, Spain

Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom

Others

Not Yet Found

Deposits in Western Continents

North America

USA

Canada, Costa Rica, Cuba, Mexico, Panama, USA

South America

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

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

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

New South Wales, New Zealand, Queensland, Victoria

Summary >>

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All about Dacite and Migmatite Properties

Know all about Dacite and Migmatite properties here. All properties of rocks are important as they define the type of rock and its application. Dacite belongs to Igneous Rocks while Migmatite belongs to Metamorphic Rocks.Texture of Dacite is Aphanitic to Porphyritic whereas that of Migmatite is Foliated. Dacite appears Vesicular and Migmatite appears Dull, Banded and Foilated. The luster of Dacite is subvitreous to dull while that of Migmatite is dull to pearly to subvitreous. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas Migmatite is available in black, bluish - grey, brown, brown- black, dark greenish - grey, dark grey to black colors. The commercial uses of Dacite are commemorative tablets, creating artwork and that of Migmatite are cemetery markers, jewelry, tombstones, used to manufracture paperweights and bookends.