Chert

Eclogite

Chert and Eclogite

Chert

Eclogite

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Definition

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

Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature

History

Origin

Discoverer

Unknown

René Just Haüy

Etymology

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

From French, Greek eklogē selection with reference to the selective content of the rock + -ite1

Class

Sedimentary Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Banded, Rough

Earthy

Color

Black, Brown, Green, Grey, Red, White

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Glassy or Pearly

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Decorative Aggregates, Interior Decoration

Exterior Uses

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

Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

Medical Industry

In Chemical and Pharmaceutical Industry, Medicines and Cosmetics

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

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

Creating Artwork, Gemstone

Types

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

Eclogite

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, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

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.

Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.

Composition

Mineral Content

Quartz, Silicon

Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite

Compound Content

Silicon Dioxide

Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Sea Erosion

Properties

Physical Properties

Hardness

6.5-73.5-4

1 7

👆🏻

Grain Size

Very fine-grained

Fine Grained

Fracture

Uneven, Splintery or Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Waxy and Dull

Subvitreous to Dull

Compressive Strength

450.00 N/mm²200.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.5

Specific Gravity

2.5-2.82.86-2.87

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.7 g/cm³3.2-3.6 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.74 kJ/Kg K0.75 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

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

India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey

Africa

Kenya, Morocco, South Africa, Tanzania

Ethiopia, Morocco, South Africa

Europe

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

France, Germany, Italy, Norway, Scotland

Others

Greenland, Mid-Atlantic Ridge

Greenland

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, Costa Rica, Panama, USA

South America

Bolivia, Brazil

Argentina, Brazil, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

Central Australia, New Zealand, Queensland

All about Chert and Eclogite Properties

Know all about Chert and Eclogite properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Eclogite belongs to Metamorphic Rocks.Texture of Chert is Banded, Rough whereas that of Eclogite is Earthy. Chert appears Glassy or Pearly and Eclogite appears Dull, Banded and Foilated. The luster of Chert is waxy and dull while that of Eclogite is subvitreous to dull. Chert is available in black, brown, green, grey, red, white colors whereas Eclogite is available in black, brown, green, grey, pink, white colors. The commercial uses of Chert and Eclogite are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.