Schist

Dacite

Schist and Dacite

Schist

Dacite

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1 Definition

1.1 Definition

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

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

1.2 History

1.2.1 Origin

Unknown

Romania and Moldova, Europe

1.2.2 Discoverer

Unknown

1.3 Etymology

From French schiste, Greek skhistos i.e. split

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

1.4 Class

Metamorphic Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

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

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Foliated, Platy

Aphanitic to Porphyritic

2.2 Color

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

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

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Metamorphic Rocks Rocks have it !

✔ ✘

81% Igneous Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

65% Metamorphic Rocks Rocks have it !

✔ ✘

86% Igneous Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

42% Metamorphic Rocks Rocks have it !

✔ ✘

66% Igneous Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

19% Metamorphic Rocks Rocks have it !

✔ ✘

49% Igneous Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

15% Metamorphic Rocks Rocks have it !

✔ ✘

48% Igneous Rocks Rocks have it !

2.5 Appearance

Layered and Shiny

Vesicular

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Floor Tiles, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, Paving Stone, Garden Decoration

3.1.3 Other Architectural Uses

Not Yet Used

Curbing

3.2 Industry

3.2.1 Construction Industry

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

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

Used in aquariums, Writing Slates

Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

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

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

4.2 Features

Easily splits into thin plates, Smooth to touch

Host Rock for Lead, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

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

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.

5.2 Composition

5.2.1 Mineral Content

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

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

5.2.2 Compound Content

CaO, Carbon Dioxide, MgO

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

50% Metamorphic Rocks Rocks have it !

✔ ✘

97% Igneous Rocks Rocks have it !

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism

5.3.3 Weathering

✔ ✘

65% Metamorphic Rocks Rocks have it !

✔ ✘

99% Igneous Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

77% Metamorphic Rocks Rocks have it !

✔ ✘

92% Igneous Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

3.5-4

2-2.25

6.1.2 Grain Size

Medium to Fine Coarse Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Shiny

Subvitreous to Dull

6.1.7 Compressive Strength

What Is Flint

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▶

▼

Not Available

Rank: N/A (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Slaty

Perfect

6.1.9 Toughness

1.5

Not Available

6.1.10 Specific Gravity

2.5-2.9

2.86-2.87

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.8-2.9 g/cm³

2.77-2.771 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

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▶

▼

Not Available

Rank: N/A (Overall)▶

0.92 kJ/Kg K

Rank: 10 (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Impact Resistant, Pressure Resistant, Water Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

Not Yet Found

7.1.2 Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Not Yet Found

7.1.3 Europe

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

France, Greece, Romania, Scotland, Spain

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

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

USA

7.2.2 South America

Brazil, Colombia, Guyana

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

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand, Queensland

New Zealand, South Australia, Western Australia

All about Schist and Dacite Properties

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