Obsidian

Travertine

Obsidian and Travertine

Obsidian

Travertine

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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

Travertine is a mineral consisting of layered calcium carbonate formed by deposition from spring waters

History

Origin

Ethiopia

Italy

Discoverer

Obsius

Marcus Vitruvius Pollio

Etymology

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

From Italian travertino a kind of building stone, from Tiburs, adjective from Tibur (Tivoli), in Italy

Class

Igneous Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Glassy

Banded

Color

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

Beige, Black, Blue, Brown, Grey, Red, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Fibrous

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Exterior Uses

Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar

Medical Industry

Surgery

Antiquity Uses

Artifacts, Jewellery

Artifacts, Jewellery, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Paper Industry, Pottery

Types

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

Thermal Travertine and Tufa

Features

Blocks negativity, Helps to protect against depression

Stalactites and stalagmites are formed from this rock, Surfaces are often shiny, Very fine grained rock

Archaeological Significance

Monuments

Famous Monuments

Colosseum in Rome, Italy, Sacré Coeur in Paris, France, Trevi Fountain in Rome, Italy

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.

Travertine is a type of sedimentary rock formed when a river carries or transports pieces of broken rock which then undergo sedimentation. They are then subjected to high temperature and pressure hence forming travertine rock.

Composition

Mineral Content

Calcite, Clay, Feldspar, Micas, Quartz

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Ca, NaCl, CaO, Oxygen

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

Properties

Physical Properties

Hardness

5-5.53-4

1 7

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Grain Size

Fine Grained

Fracture

Conchoidal

Splintery

Streak

White

Porosity

Very Less Porous

Highly Porous

Luster

Vitreous

Dull to Pearly

Compressive Strength

0.15 N/mm²80.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.6-2.71.68

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.6 g/cm³2.71 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K1.09 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

China, Russia

Africa

Kenya

Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, Italy, Portugal, United Kingdom

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Argentina, Chile, Ecuador, Peru

Argentina, Bolivia, Ecuador

Deposits in Oceania Continent

Australia

New Zealand

All about Obsidian and Travertine Properties

Know all about Obsidian and Travertine properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Travertine belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Travertine is Banded. Obsidian appears Shiny and Travertine appears Fibrous. The luster of Obsidian is vitreous while that of Travertine is dull to pearly. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Travertine is available in beige, black, blue, brown, grey, red, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Travertine are cemetery markers, creating artwork, gemstone, jewelry, paper industry, pottery.