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
Quartzite is a non-foliated metamorphic rock that forms by the metamorphism of pure quartz Sandstone
Discoverer
Obsius
Unknown
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From quartz + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Glassy
Foliated, Granular
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Black, Blue, Brown, Green, Light Grey, Purple, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Shiny
Lustrous
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Homes
Exterior Uses
Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Arrowheads, As Dimension Stone, Cement Manufacture, Construction Aggregate, Cutting Tool, for Road Aggregate, Making natural cement, Production of Glass and Ceramics, Rail Track Ballast, Roadstone
Medical Industry
Surgery
-
Antiquity Uses
Artifacts, Jewellery
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Creating Artwork, Mirror, Used in aquariums
An Oil and Gas Reservoir, As armour rock for sea walls, Cemetery Markers, Commemorative Tablets, In aquifers, Laboratory bench tops, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones, Used in aquariums
Types
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Orthoquartzite and Metaquartzite
Features
Blocks negativity, Helps to protect against depression
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
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.
Quartzite forms from sandstone and the mineral quartz being put under extreme heat and pressure.
Mineral Content
-
Chlorite, Epidote, Hematite, Kyanite, Magnetite, Muscovite or Illite, Quartz
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, MgO, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Regional 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, Water Erosion, Wind Erosion
Grain Size
-
Medium Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Very Less Porous
Less Porous
Specific Gravity
2.6-2.7
2.6-2.8
Transparency
Translucent
Transparent to Translucent
Density
2.6 g/cm3
2.32-2.42 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Indonesia, Japan, Russia
China, India, Israel, Russia, South Korea, Thailand, Turkey
Africa
Kenya
Ethiopia, Morocco, South Africa, Zimbabwe
Europe
Greece, Hungary, Iceland, Italy, Turkey
England, Italy, Norway, Scotland, Sweden, United Kingdom
Deposits in Western Continents
North America
Canada, Mexico, USA
Bahamas, Canada, USA
South America
Argentina, Chile, Ecuador, Peru
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New Zealand
New Zealand, Queensland, Western Australia
All about Obsidian and Quartzite Properties
Know all about Obsidian and Quartzite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Quartzite belongs to Metamorphic Rocks.Texture of Obsidian is Glassy whereas that of Quartzite is Foliated, Granular. Obsidian appears Shiny and Quartzite appears Lustrous. The luster of Obsidian and Quartzite is vitreous. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Quartzite is available in black, blue, brown, green, light grey, purple, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Quartzite are an oil and gas reservoir, as armour rock for sea walls, cemetery markers, commemorative tablets, in aquifers, laboratory bench tops, petroleum reservoirs, soil conditioner, source of magnesia (mgo), tombstones, used in aquariums.