Schist

Greywacke

Schist and Greywacke

Schist

Greywacke

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Definition

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

Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay

History

Origin

Discoverer

Unknown

Etymology

From French schiste, Greek skhistos i.e. split

From German Grauwacke, from grau grey + wacke

Class

Metamorphic Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Foliated, Platy

Clastic

Color

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

Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered and Shiny

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Interior Decoration

Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

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

Other Architectural Uses

Curbing, Whetstones

Industry

Construction Industry

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

Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

Used in aquariums, Writing Slates

As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones

Types

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

Greywacke

Features

Easily splits into thin plates, Smooth to touch

Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

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.

Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.

Composition

Mineral Content

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

Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Compound Content

CaO, Carbon Dioxide, MgO

Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Coastal Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

3.5-46-7

1 7

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Grain Size

Medium to Fine Coarse Grained

Angular and Fine

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Luster

Shiny

Dull

Compressive Strength

150.00 N/mm²120.00 N/mm²

0.15 450

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Cleavage

Slaty

Perfect

Toughness

1.5

2.6

Specific Gravity

2.5-2.92.2-2.8

0 8.4

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Transparency

Opaque

Density

2.8-2.9 g/cm³2.6-2.61 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant, Water Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Namibia, Nigeria, South Africa

Europe

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

Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom

Others

Greenland

Deposits in Western Continents

North America

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

Canada, USA

South America

Brazil, Colombia, Guyana

Brazil

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland

New South Wales, New Zealand

All about Schist and Greywacke Properties

Know all about Schist and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Schist belongs to Metamorphic Rocks while Greywacke belongs to Sedimentary Rocks.Texture of Schist is Foliated, Platy whereas that of Greywacke is Clastic. Schist appears Layered and Shiny and Greywacke appears Dull. The luster of Schist is shiny while that of Greywacke is dull. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas Greywacke is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Schist are used in aquariums, writing slates and that of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.