Trondhjemite

Mylonite

Trondhjemite and Mylonite

Trondhjemite

Mylonite

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Definition

Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.

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

History

Origin

Tonale, Italy

New Zealand

Discoverer

Unknown

Etymology

From Trondheim, Norway

From Greek mulōn mill + -ite

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Phaneritic

Foliated

Color

Black, Brown, Light to Dark Grey, White

Black to Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded and Foilated

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate

for Road Aggregate, Landscaping, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork, Gemstone, Jewelry

Types

Intermediate intrusive rock

Blastomylonites, Ultramylonites and Phyllonites

Features

Is one of the oldest rock, Typically speckled black and white.

Surfaces are often shiny

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.

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

Composition

Mineral Content

Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon

Porphyroblasts

Compound Content

NaCl, CaO, MgO, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6-73-4

1 7

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Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Streak

Bluish Black

White

Porosity

Very Less Porous

Highly Porous

Luster

Subvitreous to Dull

Shiny

Compressive Strength

130.00 N/mm²1.28 N/mm²

0.15 450

👆🏻

Cleavage

Conchoidal

Toughness

2.1

Specific Gravity

2.86-32.97-3.05

0 8.4

👆🏻

Transparency

Opaque

Density

2.73 g/cm³2.6-4.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K1.50 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Indonesia, Saudi Arabia, South Korea

Africa

Egypt

Eritrea, Ethiopia, Ghana, South Africa, Western Africa

Europe

Finland, Germany, Italy, Romania, Sweden, Turkey

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

Others

Deposits in Western Continents

North America

USA

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

Central Australia, Western Australia

All about Trondhjemite and Mylonite Properties

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