Trondhjemite

Schist

Trondhjemite and Schist

Trondhjemite

Schist

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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.

Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation

History

Origin

Tonale, Italy

Discoverer

Unknown

Etymology

From Trondheim, Norway

From French schiste, Greek skhistos i.e. split

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

Texture

Phaneritic

Foliated, Platy

Color

Black, Brown, Light to Dark Grey, White

Black, Blue, Brown, Dark Brown, Green, Grey, Silver

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded and Foilated

Layered and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Floor Tiles, Interior Decoration

Exterior Uses

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

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Used in aquariums, Writing Slates

Types

Intermediate intrusive rock

Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.

Features

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

Easily splits into thin plates, Smooth to touch

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.

Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.

Composition

Mineral Content

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

Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc

Compound Content

NaCl, CaO, MgO, Silicon Dioxide

CaO, Carbon Dioxide, MgO

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, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

6-73.5-4

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

Bluish Black

White

Porosity

Very Less Porous

Highly Porous

Luster

Subvitreous to Dull

Shiny

Compressive Strength

130.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.1

1.5

Specific Gravity

2.86-32.5-2.9

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 K0.70 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Impact Resistant, Pressure Resistant, Water Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam

Africa

Egypt

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Europe

Finland, Germany, Italy, Romania, Sweden, Turkey

Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland

Others

Deposits in Western Continents

North America

USA

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

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru

Brazil, Colombia, Guyana

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

New South Wales, New Zealand, Queensland

All about Trondhjemite and Schist Properties

Know all about Trondhjemite and Schist properties here. All properties of rocks are important as they define the type of rock and its application. Trondhjemite belongs to Igneous Rocks while Schist belongs to Metamorphic Rocks.Texture of Trondhjemite is Phaneritic whereas that of Schist is Foliated, Platy. Trondhjemite appears Banded and Foilated and Schist appears Layered and Shiny. The luster of Trondhjemite is subvitreous to dull while that of Schist is shiny. Trondhjemite is available in black, brown, light to dark grey, white colors whereas Schist is available in black, blue, brown, dark brown, green, grey, silver colors. The commercial uses of Trondhjemite are cemetery markers, creating artwork and that of Schist are used in aquariums, writing slates.