Definition
Trachyandesite is an extrusive igneous rock.
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
Origin
Indonesia
Ethiopia
Discoverer
Unknown
Obsius
Etymology
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Glassy
Color
Black, Brown, Light to Dark Grey
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Shiny
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
Not Yet Used
Surgery
Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery
Commercial Uses
Creating Artwork, Pottery
Creating Artwork, Mirror, Used in aquariums
Types
Basaltic Trachyandesite
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Blocks negativity, Helps to protect against depression
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
Formation
Trachyandesite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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.
Mineral Content
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Not Available
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional 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, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Not Applicable
Fracture
Conchoidal
Conchoidal
Streak
Light to dark brown
White
Porosity
Less Porous
Very Less Porous
Cleavage
Perfect
Non-Existent
Toughness
2.3
Not Available
Specific Gravity
2.8-3
2.6-2.7
Transparency
Opaque
Translucent
Density
2.9-3.1 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Russia
Afghanistan, Indonesia, Japan, Russia
Africa
South Africa
Kenya
Europe
Iceland
Greece, Hungary, Iceland, Italy, Turkey
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand
All about Trachyandesite and Obsidian Properties
Know all about Trachyandesite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Trachyandesite and Obsidian belong to Igneous Rocks.Texture of Trachyandesite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Obsidian is Glassy. Trachyandesite appears Dull and Soft and Obsidian appears Shiny. The luster of Trachyandesite is earthy while that of Obsidian is vitreous. Trachyandesite is available in black, brown, light to dark grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Trachyandesite are creating artwork, pottery and that of Obsidian are creating artwork, mirror, used in aquariums.