Chert

Appinite

Chert and Appinite

Chert

Appinite

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Definition

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

Appinite is an igneous rock in which the crystals are so fine grained that individual minerals cannot be easily distinguished

History

Origin

Discoverer

Unknown

Etymology

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

From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Opaque Rock

Texture

Banded, Rough

Porphyritic

Color

Black, Brown, Green, Grey, Red, White

Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey

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, Homes, Interior Decoration

Exterior Uses

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

Paving Stone, Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Whetstones

Industry

Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Taken as a Supplement for Calcium or Magnesium

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, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner

Types

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

Igneous rock

Features

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

Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny

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.

The formation of Appinite takes place deep beneath the Earth’s surface at around 150 to 450 kms, and are erupted rapidly and violently.

Composition

Mineral Content

Quartz, Silicon

Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene

Compound Content

Silicon Dioxide

Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6.5-75-6

1 7

👆🏻

Grain Size

Very fine-grained

Fine to Coarse Grained

Fracture

Uneven, Splintery or Conchoidal

Conchoidal

Streak

White

Porosity

Highly Porous

Very Less Porous

Luster

Waxy and Dull

Subvitreous to Dull

Compressive Strength

450.00 N/mm²185.00 N/mm²

0.15 450

👆🏻

Cleavage

Conchoidal

Toughness

1.5

Specific Gravity

2.5-2.82.86-2.87

0 8.4

👆🏻

Transparency

Translucent to Opaque

Density

2.7 g/cm³2.95-2.96 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

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Russia

Africa

Kenya, Morocco, South Africa, Tanzania

Angola, Botswana, Cameroon, Ethiopia, South Africa

Europe

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

England, Hungary, Iceland, United Kingdom

Others

Greenland, Mid-Atlantic Ridge

Antarctica, Greenland

Deposits in Western Continents

North America

Canada, Mexico, USA

South America

Bolivia, Brazil

Argentina, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

New South Wales, New Zealand, Queensland, South Australia, Western Australia

All about Chert and Appinite Properties

Know all about Chert and Appinite properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Appinite belongs to Igneous Rocks.Texture of Chert is Banded, Rough whereas that of Appinite is Porphyritic. Chert appears Glassy or Pearly and Appinite appears Dull, Banded and Foilated. The luster of Chert is waxy and dull while that of Appinite is subvitreous to dull. Chert is available in black, brown, green, grey, red, white colors whereas Appinite is available in black, bluish - grey, brown, dark greenish - grey, green, grey 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 Appinite are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner.