Chert and Borolanite

Chert

Borolanite

Definition

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

Borolanite is a variety of Nepheline Syenite and belongs to igneous rocks and contains nepheline-alkali feldspar pseudomorphs which occur as conspicuous white spots in the dark rock matrix

History

Origin

Unknown

Scotland

Discoverer

Unknown

Etymology

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

From Alkalic Igneous complex near Loch Borralan in northwest Scotland

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Not Applicable

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Banded, Rough

Granular

Color

Black, Brown, Green, Grey, Red, White

Brown, Buff, Cream, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Yes

Wind Resistant

Yes

Acid Resistant

Yes

Appearance

Glassy or Pearly

Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration

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, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

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

Cemetery Markers

Types

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

Not Available

Features

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

Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock

Archaeological Significance

Monuments

Used

Famous Monuments

Data Not Available

Sculpture

Not Yet Used

Used

Famous Sculptures

Not Applicable

Data Not Available

Pictographs

Not Used

Used

Petroglyphs

Not Used

Used

Figurines

Not Yet Used

Used

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.

Borolanites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

Composition

Mineral Content

Quartz, Silicon

Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite

Compound Content

Silicon Dioxide

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

Transformation

Metamorphism

Yes

Types of Metamorphism

Not Applicable

Regional Metamorphism

Weathering

Yes

Types of Weathering

Not Applicable

Chemical Weathering, Mechanical Weathering

Erosion

Yes

Types of Erosion

Chemical Erosion

Wind Erosion

Properties

Physical Properties

Hardness

6.5-7

5.5-6

Grain Size

Very fine-grained

Fine Grained

Fracture

Uneven, Splintery or Conchoidal

Conchoidal to Uneven

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Waxy and Dull

Greasy to Dull

Compressive Strength

450.00 N/mm²

150.00 N/mm²

Cleavage

Non-Existent

Poor

Toughness

1.5

Not Available

Specific Gravity

2.5-2.8

2.6

Transparency

Translucent to Opaque

Density

2.7 g/cm³

2.6 g/cm³

Thermal Properties

Specific Heat Capacity

0.74 kJ/Kg K

Not Available

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam

Africa

Kenya, Morocco, South Africa, Tanzania

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Europe

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

Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden

Others

Greenland, Mid-Atlantic Ridge

Greenland

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Bolivia, Brazil

Brazil, Chile, Colombia, Uruguay, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

New Zealand, Queensland, South Australia, Tasmania, Western Australia

Summary >>

<< Reserves

All about Chert and Borolanite Properties

Know all about Chert and Borolanite properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Borolanite belongs to Igneous Rocks.Texture of Chert is Banded, Rough whereas that of Borolanite is Granular. Chert appears Glassy or Pearly and Borolanite appears Banded and Foilated. The luster of Chert is waxy and dull while that of Borolanite is greasy to dull. Chert is available in black, brown, green, grey, red, white colors whereas Borolanite is available in brown, buff, cream, green, grey, pink, white 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 Borolanite are cemetery markers.