Chert

Diabase

Chert and Diabase

Chert

Diabase

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Definition

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

Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar

History

Origin

Germany

Discoverer

Unknown

Christian Leopold von Buch

Etymology

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

From Greek di + base

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Banded, Rough

Aphanitic, Granular

Color

Black, Brown, Green, Grey, Red, White

Dark Grey to Black

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Glassy or Pearly

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

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

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones

Types

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

Dolerite

Features

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

Smooth to touch

Archaeological Significance

Monuments

Famous Monuments

Stonehenge in English county of Wiltshire

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.

Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.

Composition

Mineral Content

Quartz, Silicon

Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine

Compound Content

Silicon Dioxide

Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Properties

Physical Properties

Hardness

6.5-77

1 7

👆🏻

Grain Size

Very fine-grained

Fine to Medium Grained

Fracture

Uneven, Splintery or Conchoidal

Conchoidal

Streak

White

Black

Porosity

Highly Porous

Luster

Waxy and Dull

Compressive Strength

450.00 N/mm²225.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.5

1.6

Specific Gravity

2.5-2.82.86-2.87

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.7 g/cm³2.7-3.3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.74 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

India

Africa

Kenya, Morocco, South Africa, Tanzania

South Africa, Tanzania

Europe

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

Germany, Greece, Italy, Scotland, Turkey

Others

Greenland, Mid-Atlantic Ridge

Antarctica, Greenland

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Bolivia, Brazil

Argentina, Brazil, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

Central Australia, New Zealand, Queensland, Western Australia

All about Chert and Diabase Properties

Know all about Chert and Diabase properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Diabase belongs to Igneous Rocks.Texture of Chert is Banded, Rough whereas that of Diabase is Aphanitic, Granular. Chert appears Glassy or Pearly and Diabase appears Vesicular. The luster of Chert is waxy and dull while that of Diabase is . Chert is available in black, brown, green, grey, red, white colors whereas Diabase is available in dark grey to black 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 Diabase are an oil and gas reservoir, cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.