Trondhjemite

Skarn

Trondhjemite and Skarn

Trondhjemite

Skarn

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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.

Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin

History

Origin

Tonale, Italy

USA, Australia

Discoverer

Unknown

Tornebohm

Etymology

From Trondheim, Norway

From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Phaneritic

Earthy, Mud-rich, Rough

Color

Black, Brown, Light to Dark Grey, White

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded and Foilated

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)

Types

Intermediate intrusive rock

Endoskarns

Features

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

Host Rock for Lead, Zinc and Copper Deposits

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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

Composition

Mineral Content

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

Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite

Compound Content

NaCl, CaO, MgO, Silicon Dioxide

Au, CaO, Carbon Dioxide, Cu, Fe, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional 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, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6-76.5

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Irregular

Streak

Bluish Black

Light to dark brown

Porosity

Very Less Porous

Less Porous

Luster

Subvitreous to Dull

Waxy and Dull

Compressive Strength

130.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.1

2.4

Specific Gravity

2.86-32.86

0 8.4

👆🏻

Transparency

Opaque

Density

2.73 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Russia, Saudi Arabia, South Korea, Sri Lanka

Africa

Egypt

South Africa, Western Africa

Europe

Finland, Germany, Italy, Romania, Sweden, Turkey

United Kingdom

Others

Deposits in Western Continents

North America

USA

Canada

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru

Brazil, Colombia, Paraguay

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

Central Australia, Western Australia

All about Trondhjemite and Skarn Properties

Know all about Trondhjemite and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Trondhjemite belongs to Igneous Rocks while Skarn belongs to Metamorphic Rocks.Texture of Trondhjemite is Phaneritic whereas that of Skarn is Earthy, Mud-rich, Rough. Trondhjemite appears Banded and Foilated and Skarn appears Dull. The luster of Trondhjemite is subvitreous to dull while that of Skarn is waxy and dull. Trondhjemite is available in black, brown, light to dark grey, white colors whereas Skarn is available in black, brown, green, grey, white colors. The commercial uses of Trondhjemite are cemetery markers, creating artwork and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).