Chert

Greywacke

Chert and Greywacke

Chert

Greywacke

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1 Definition

1.1 Definition

Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture

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

1.2 History

1.2.1 Origin

Unknown

1.2.2 Discoverer

Unknown

1.3 Etymology

From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use

From German Grauwacke, from grau grey + wacke

1.4 Class

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Banded, Rough

Clastic

2.2 Color

Black, Brown, Green, Grey, Red, White

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

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Glassy or Pearly

Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes

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

3.1.2 Exterior Uses

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

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

3.1.3 Other Architectural Uses

Curbing

Curbing, Whetstones

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments

Artifacts, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms

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

4 Types

4.1 Types

Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter

Not Available

4.2 Features

Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate

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

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Present

5 Formation

5.1 Formation

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

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.

5.2 Composition

5.2.1 Mineral Content

Quartz, Silicon

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

5.2.2 Compound Content

Silicon Dioxide

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Not Applicable

Biological Weathering, Chemical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion

Coastal Erosion, Sea Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.5-76-7

1 7

6.1.2 Grain Size

Very fine-grained

Angular and Fine

6.1.3 Fracture

Uneven, Splintery or Conchoidal

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

6.1.6 Luster

Waxy and Dull

Dull

6.1.7 Compressive Strength

450.00 N/mm²NA

0.15 450

6.1.8 Cleavage

Non-Existent

Perfect

6.1.9 Toughness

1.5

2.6

6.1.10 Specific Gravity

2.5-2.82.2-2.8

0 8.4

6.1.11 Transparency

Translucent to Opaque

Opaque

6.1.12 Density

2.7 g/cm³2.6-2.61 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.74 kJ/Kg KNA

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

7.1.2 Africa

Kenya, Morocco, South Africa, Tanzania

Namibia, Nigeria, South Africa

7.1.3 Europe

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

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

7.1.4 Others

Greenland, Mid-Atlantic Ridge

Greenland

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, USA

7.2.2 South America

Bolivia, Brazil

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, Queensland, South Australia, Western Australia

New South Wales, New Zealand

All about Chert and Greywacke Properties

Know all about Chert and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Chert and Greywacke belong to Sedimentary Rocks.Texture of Chert is Banded, Rough whereas that of Greywacke is Clastic. Chert appears Glassy or Pearly and Greywacke appears Dull. The luster of Chert is waxy and dull while that of Greywacke is dull. Chert is available in black, brown, green, grey, red, white colors whereas Greywacke is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.