Obsidian

Coquina

Obsidian vs Coquina

Obsidian

Coquina

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Definition

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth

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

Ethiopia

European Foreland Basins

Discoverer

Obsius

Unknown

Etymology

From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

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

Volcanic

Other Categories

Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Glassy

Clastic

Color

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

Beige, Buff, Orange

Maintenance

Less

Durability

Durable

Non-Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Hotels, Interior Decoration

Exterior Uses

Garden Decoration

Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Building houses or walls, Construction Aggregate

Medical Industry

Surgery

Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Creating Artwork

Types

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

Sedimentary rock

Features

Blocks negativity, Helps to protect against depression

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

When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.

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

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

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

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

Chemical Erosion, Coastal Erosion, Glacier Erosion

Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

5-5.51-2

1 7

👆🏻

Grain Size

Coarse Grained

Fracture

Conchoidal

Irregular

Streak

White

Porosity

Very Less Porous

Highly Porous

Luster

Vitreous

Dull to Vitreous to Submetallic

Compressive Strength

0.15 N/mm²-

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.6-2.71.10-2.24

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.6 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

Africa

Kenya

Europe

Greece, Hungary, Iceland, Italy, Turkey

United Kingdom

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

Obsidian vs Coquina Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Obsidian and Coquina Reserves. Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth. 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. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Obsidian vs Coquina information and Obsidian vs Coquina characteristics in the upcoming sections.

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Obsidian vs Coquina Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Obsidian vs Coquina characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Coquina. Learn more about Obsidian vs Coquina in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Coquina include Decorative aggregates, Homes, Hotels and Interior decoration. Due to some exceptional properties of Obsidian and Coquina, they have various applications in construction industry. The uses of Obsidian in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Coquina include Building houses or walls, Construction aggregate.

More about Obsidian and Coquina

Here you can know more about Obsidian and Coquina. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Coquina consists of mineral content and compound content. The mineral content of Obsidian includes and mineral content of Coquina includes Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Coquina, the texture, color and appearance plays an important role in determining the type of rock. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas, Coquina is available in beige, buff, orange colors. Appearance of Obsidian is Shiny and that of Coquina is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Obsidian vs Coquina. The hardness of Obsidian is 5-5.5 and that of Coquina is 1-2. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Coquina are Sedimentary rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian and Coquina is white. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Coquina is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Obsidian is heat resistant, impact resistant whereas Coquina is heat resistant, impact resistant, pressure resistant, wear resistant.