Dunite

Coquina

Dunite and Coquina

Dunite

Coquina

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Definition

Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine

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

History

Origin

New Zealand

European Foreland Basins

Discoverer

Ferdinand von Hochstetter

Unknown

Etymology

From the name of Dun Mountain, New Zealand, + -ite1

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

Class

Igneous Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Texture

Phaneritic

Clastic

Color

Dark Greenish - Grey

Beige, Buff, Orange

Maintenance

Less

Durability

Durable

Non-Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Shiny

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Hotels, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Building houses or walls, Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds

Creating Artwork

Types

Dunite

Sedimentary rock

Features

Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

Formation

Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.

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.

Composition

Mineral Content

Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene

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

Compound Content

Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

3.5-41-2

1 7

👆🏻

Grain Size

Coarse Grained

Fracture

Irregular

Streak

White

Porosity

Less Porous

Highly Porous

Luster

Shiny

Dull to Vitreous to Submetallic

Compressive Strength

107.55 N/mm²-

0.15 450

👆🏻

Cleavage

Toughness

2.1

Specific Gravity

3-3.011.10-2.24

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.84-2.85 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.25 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey

Africa

Morocco, South Africa

Europe

Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland

United Kingdom

Others

Deposits in Western Continents

North America

Canada, USA

USA

South America

Argentina, Brazil, Colombia, Ecuador, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

All about Dunite and Coquina Properties

Know all about Dunite and Coquina properties here. All properties of rocks are important as they define the type of rock and its application. Dunite belongs to Igneous Rocks while Coquina belongs to Sedimentary Rocks.Texture of Dunite is Phaneritic whereas that of Coquina is Clastic. Dunite appears Rough and Shiny and Coquina appears Layered, Banded, Veined and Shiny. The luster of Dunite is shiny while that of Coquina is dull to vitreous to submetallic. Dunite is available in dark greenish - grey colors whereas Coquina is available in beige, buff, orange colors. The commercial uses of Dunite and Coquina are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.