Dacite

Coquina

Dacite and Coquina

Dacite

Coquina

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1 Definition

1.1 Definition

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

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

1.2 History

1.2.1 Origin

Romania and Moldova, Europe

European Foreland Basins

1.2.2 Discoverer

Unknown

1.3 Etymology

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

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

1.4 Class

Igneous Rocks

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic to Porphyritic

Clastic

2.2 Color

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

Beige, Buff, Orange

2.3 Maintenance

Less

2.4 Durability

Durable

Non-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

Vesicular

Layered, Banded, Veined and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Homes, Hotels, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

Garden Decoration, Office Buildings

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

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

Building houses or walls, Construction Aggregate

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Commemorative Tablets, Creating Artwork

Creating Artwork

4 Types

4.1 Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Not Available

4.2 Features

Host Rock for Lead, Is one of the oldest rock

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

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

Present

5 Formation

5.1 Formation

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.

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.

5.2 Composition

5.2.1 Mineral Content

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

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

5.2.2 Compound Content

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

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Not Applicable

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

Chemical Erosion

Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

2-2.251-2

1 7

6.1.2 Grain Size

Medium to Fine Coarse Grained

Coarse Grained

6.1.3 Fracture

Conchoidal

Irregular

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Subvitreous to Dull

Dull to Vitreous to Submetallic

6.1.7 Compressive Strength

NANA

0.15 450

6.1.8 Cleavage

Perfect

Not Available

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.86-2.871.10-2.24

0 8.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.77-2.771 g/cm³2.8-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg KNA

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

France, Greece, Romania, Scotland, Spain

United Kingdom

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

USA

7.2.2 South America

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

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, South Australia, Western Australia

Not Yet Found

All about Dacite and Coquina Properties

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