Coquina

Dacite

Coquina and Dacite

Coquina

Dacite

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1 Definition

1.1 Definition

Coquina is a sedimentary rock that is composed either wholly or almost entirely of the transported, abraded, and mechanically-sorted fragments of the shells of molluscs, trilobites, brachiopods, or other invertebrates

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

1.2 History

1.2.1 Origin

European Foreland Basins

Romania and Moldova, Europe

1.2.2 Discoverer

Unknown

1.3 Etymology

From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)

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, Soft Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Clastic

Aphanitic to Porphyritic

2.2 Color

Beige, Buff, Orange

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

2.3 Maintenance

Less

2.4 Durability

Non-Durable

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Layered, Banded, Veined and Shiny

Vesicular

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Hotels, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

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

Building houses or walls, Construction Aggregate

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork

Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Not Available

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

4.2 Features

Available in Lots of Colors and Patterns, Is one of the oldest rock

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

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Present

Absent

5 Formation

5.1 Formation

Coquina is a sedimentary rock which is formed when billions of small clam-like seashell, called Coquina, or cockleshell are die and hence are deposited, buried and turns into a rock when pressure is applied.

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

Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite

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

5.2.2 Compound Content

CaO, Carbon Dioxide, Iron(III) Oxide, MgO

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

1-22-2.25

1 7

6.1.2 Grain Size

Coarse Grained

Medium to Fine Coarse Grained

6.1.3 Fracture

Irregular

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Dull to Vitreous to Submetallic

Subvitreous to Dull

6.1.7 Compressive Strength

NANA

0.15 450

6.1.8 Cleavage

Not Available

Perfect

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

1.10-2.242.86-2.87

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.8-2.9 g/cm³2.77-2.771 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Not Yet Found

7.1.2 Africa

Not Yet Found

7.1.3 Europe

United Kingdom

France, Greece, Romania, Scotland, Spain

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

USA

7.2.2 South America

Not Yet Found

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

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New Zealand, South Australia, Western Australia

All about Coquina and Dacite Properties

Know all about Coquina and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Coquina belongs to Sedimentary Rocks while Dacite belongs to Igneous Rocks.Texture of Coquina is Clastic whereas that of Dacite is Aphanitic to Porphyritic. Coquina appears Layered, Banded, Veined and Shiny and Dacite appears Vesicular. The luster of Coquina is dull to vitreous to submetallic while that of Dacite is subvitreous to dull. Coquina is available in beige, buff, orange colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Coquina are creating artwork and that of Dacite are commemorative tablets, creating artwork.