Foidolite

Chert

Foidolite and Chert

Foidolite

Chert

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Definition

Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%

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

History

Origin

Discoverer

Unknown

Etymology

From the mineral feldspathoid which is the main content of rock

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

Class

Igneous Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Earthy

Banded, Rough

Color

Black, Brown, Green, Grey, Pink, White

Black, Brown, Green, Grey, Red, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Glassy or Pearly

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, for Road Aggregate

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

Medical Industry

Taken as a Supplement for Calcium or Magnesium

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

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

Types

Igneous rock

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

Features

Host Rock for Lead

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

Formation

Foidolites is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

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.

Composition

Mineral Content

Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene

Quartz, Silicon

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO

Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

1.56.5-7

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Very fine-grained

Fracture

Conchoidal

Uneven, Splintery or Conchoidal

Streak

White

Porosity

Very Less Porous

Highly Porous

Luster

Subvitreous to Dull

Waxy and Dull

Compressive Strength

80.00 N/mm²450.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.5

Specific Gravity

2.862.5-2.8

0 8.4

👆🏻

Transparency

Translucent

Translucent to Opaque

Density

-9999 g/cm³2.7 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.79 kJ/Kg K0.74 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Russia

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

Africa

South Africa, Western Africa

Kenya, Morocco, South Africa, Tanzania

Europe

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

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, USA

Canada, Mexico, USA

South America

Bolivia, Brazil

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

New South Wales, Queensland, South Australia, Western Australia

All about Foidolite and Chert Properties

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