Chert

Andesite

Chert and Andesite

Chert

Andesite

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Definition

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

Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava

History

Origin

North America

Discoverer

Unknown

Theodor von Gümbel

Etymology

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

From Andes mountains, where it is found in abundance

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Banded, Rough

Aphanitic to Porphyritic

Color

Black, Brown, Green, Grey, Red, White

Bluish - Grey, Grey, Pink, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Glassy or Pearly

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

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

Exterior Uses

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

Office Buildings, Roof Tiles

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

Cobblestones, 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

Commemorative Tablets, Creating Artwork

Types

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

Icelandite

Features

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

Generally rough to touch, High silica content, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Middle of the Earth in Ecuador

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.

Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.

Composition

Mineral Content

Quartz, Silicon

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

Compound Content

Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

6.5-77

1 7

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Grain Size

Very fine-grained

Fracture

Uneven, Splintery or Conchoidal

Uneven

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Waxy and Dull

Vitreous

Compressive Strength

450.00 N/mm²225.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.5

1.1

Specific Gravity

2.5-2.82.5-2.8

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.7 g/cm³2.11-2.36 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.74 kJ/Kg K2.39 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

India, Indonesia, Japan, Nepal, South Korea

Africa

Kenya, Morocco, South Africa, Tanzania

Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania

Europe

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

Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, Mexico, USA

Mexico, USA

South America

Bolivia, Brazil

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

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

New South Wales, New Zealand, Western Australia

All about Chert and Andesite Properties

Know all about Chert and Andesite properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Andesite belongs to Igneous Rocks.Texture of Chert is Banded, Rough whereas that of Andesite is Aphanitic to Porphyritic. Chert appears Glassy or Pearly and Andesite appears Dull and Soft. The luster of Chert is waxy and dull while that of Andesite is vitreous. Chert is available in black, brown, green, grey, red, white colors whereas Andesite is available in bluish - grey, grey, pink, 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 Andesite are commemorative tablets, creating artwork.