Variolite

Coquina

Variolite and Coquina

Variolite

Coquina

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1 Definition

1.1 Definition

Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance

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

France

European Foreland Basins

1.2.2 Discoverer

Unknown

1.3 Etymology

From Latin varius, speckled, variegated

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, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Opaque Rock

Coarse Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Clastic

2.2 Color

Black, Brown, 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

Dull and Soft

Layered, Banded, Veined and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Homes, Hotels, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Office Buildings

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Building houses or walls, Construction Aggregate

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork

4 Types

4.1 Types

Not Available

4.2 Features

Has High structural resistance against erosion and climate, Very fine grained rock

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

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Used

4.4 Fossils

Absent

Present

5 Formation

5.1 Formation

Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.

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

Olivine, Plagioclase, Pyroxene

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

5.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium 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, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional 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

Not Applicable

Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

61-2

1 7

6.1.2 Grain Size

Not Applicable

Coarse Grained

6.1.3 Fracture

Conchoidal

Irregular

6.1.4 Streak

White to Grey

White

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Not Available

Dull to Vitreous to Submetallic

6.1.7 Compressive Strength

37.50 N/mm²NA

0.15 450

6.1.8 Cleavage

Not Available

6.1.9 Toughness

2.3

Not Available

6.1.10 Specific Gravity

2.8-31.10-2.24

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

2.9-3.1 g/cm³2.8-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.84 kJ/Kg KNA

0.14 3.2

6.2.2 Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Russia

Not Yet Found

7.1.2 Africa

South Africa

Not Yet Found

7.1.3 Europe

Iceland

United Kingdom

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

USA

7.2.2 South America

Brazil

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

All about Variolite and Coquina Properties

Know all about Variolite and Coquina properties here. All properties of rocks are important as they define the type of rock and its application. Variolite belongs to Igneous Rocks while Coquina belongs to Sedimentary Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Coquina is Clastic. Variolite appears Dull and Soft and Coquina appears Layered, Banded, Veined and Shiny. The luster of Variolite is not available while that of Coquina is dull to vitreous to submetallic. Variolite is available in black, brown, light to dark grey colors whereas Coquina is available in beige, buff, orange colors. The commercial uses of Variolite and Coquina are cemetery markers, creating artwork.