Chert

Dacite

Chert and Dacite

Chert

Dacite

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1 Definition

1.1 Definition

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

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

1.2 History

1.2.1 Origin

Unknown

Romania and Moldova, Europe

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

1.4 Class

Sedimentary Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Banded, Rough

Aphanitic to Porphyritic

2.2 Color

Black, Brown, Green, Grey, Red, White

Bluish - Grey, Brown, Grey, Light to Dark Grey

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

59% Sedimentary Rocks Rocks have it !

✔ ✘

81% Igneous Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

62% Sedimentary Rocks Rocks have it !

✔ ✘

86% Igneous Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

43% Sedimentary Rocks Rocks have it !

✔ ✘

66% Igneous Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

38% Sedimentary Rocks Rocks have it !

✔ ✘

49% Igneous Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

22% Sedimentary Rocks Rocks have it !

✔ ✘

48% Igneous Rocks Rocks have it !

2.5 Appearance

Glassy or Pearly

Vesicular

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

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

As Building Stone, Paving Stone, Garden Decoration

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

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

Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

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

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

4.2 Features

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

Host Rock for Lead, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Present

Absent

5 Formation

5.1 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.

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

5.2 Composition

5.2.1 Mineral Content

Quartz, Silicon

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

5.2.2 Compound Content

Silicon Dioxide

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

19% Sedimentary Rocks Rocks have it !

✔ ✘

97% Igneous Rocks Rocks have it !

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism

5.3.3 Weathering

✔ ✘

78% Sedimentary Rocks Rocks have it !

✔ ✘

99% Igneous Rocks Rocks have it !

5.3.4 Types of Weathering

Not Applicable

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

86% Sedimentary Rocks Rocks have it !

✔ ✘

92% Igneous Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.5-7

2-2.25

6.1.2 Grain Size

Very fine-grained

Medium to Fine Coarse Grained

6.1.3 Fracture

Uneven, Splintery or Conchoidal

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Waxy and Dull

Subvitreous to Dull

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

450.00 N/mm²

Rank: 1 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Non-Existent

Perfect

6.1.9 Toughness

1.5

Not Available

6.1.10 Specific Gravity

2.5-2.8

2.86-2.87

6.1.11 Transparency

Translucent to Opaque

Translucent

6.1.12 Density

2.7 g/cm³

2.77-2.771 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.74 kJ/Kg K

Rank: 19 (Overall)▶

0.92 kJ/Kg K

Rank: 10 (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

Not Yet Found

7.1.2 Africa

Kenya, Morocco, South Africa, Tanzania

Not Yet Found

7.1.3 Europe

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

France, Greece, Romania, Scotland, Spain

7.1.4 Others

Greenland, Mid-Atlantic Ridge

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

USA

7.2.2 South America

Bolivia, Brazil

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

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, Queensland, South Australia, Western Australia

New Zealand, South Australia, Western Australia

All about Chert and Dacite Properties

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