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
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
Durable Rock, Medium Hardness Rock
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Beige, Black, Blue, Brown, Grey, Red, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
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
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
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
Famous Monuments
-
Colosseum in Rome, Italy, Sacré Coeur in Paris, France, Trevi Fountain in Rome, Italy
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.
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
-
Fine Grained
Fracture
Conchoidal
Splintery
Porosity
Very Less Porous
Highly Porous
Luster
Vitreous
Dull to Pearly
Specific Gravity
2.6-2.7
1.68
Transparency
Translucent
Opaque
Density
2.6 g/cm3
2.71 g/cm3
Resistance
Heat Resistant, Impact Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
China, Russia
Europe
Greece, Hungary, Iceland, Italy, Turkey
Austria, Italy, Portugal, United Kingdom
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Argentina, Chile, Ecuador, Peru
Argentina, Bolivia, Ecuador
Deposits in Oceania Continent
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.