Mylonite

Dacite

Mylonite and Dacite

Mylonite

Dacite

Add ⊕

Definition

Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism

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

History

Origin

New Zealand

Romania and Moldova, Europe

Discoverer

Unknown

Etymology

From Greek mulōn mill + -ite

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

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Foliated

Aphanitic to Porphyritic

Color

Black to Grey

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull, Banded and Foilated

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Paving Stone, Garden Decoration

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Landscaping, Roadstone

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

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Commemorative Tablets, Creating Artwork

Types

Blastomylonites, Ultramylonites and Phyllonites

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

Surfaces are often shiny

Host Rock for Lead, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.

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

Porphyroblasts

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

Compound Content

Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

3-42-2.25

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Shiny

Subvitreous to Dull

Compressive Strength

1.28 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Conchoidal

Perfect

Toughness

Specific Gravity

2.97-3.052.86-2.87

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.6-4.8 g/cm³2.77-2.771 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.50 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Indonesia, Saudi Arabia, South Korea

Africa

Eritrea, Ethiopia, Ghana, South Africa, Western Africa

Europe

England, Finland, France, Germany, Great Britain, Greece, United Kingdom

France, Greece, Romania, Scotland, Spain

Others

Deposits in Western Continents

North America

USA

South America

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

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New Zealand, South Australia, Western Australia

All about Mylonite and Dacite Properties

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