Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Texture
Color
Maintenance
Durability
Water Resistant
Scratch Resistant
Stain Resistant
Wind Resistant
Acid Resistant
Appearance
Interior Uses
Exterior Uses
Other Architectural Uses
Construction Industry
Medical Industry
Antiquity Uses
Commercial Uses
Types
Features
Monuments
Famous Monuments
Sculpture
Famous Sculptures
Pictographs
Petroglyphs
Figurines
Fossils
Formation
Mineral Content
Compound Content
Metamorphism
Types of Metamorphism
Weathering
Types of Weathering
Erosion
Types of Erosion
Hardness
Grain Size
Fracture
Streak
Porosity
Luster
Compressive Strength
Cleavage
Toughness
Specific Gravity
Transparency
Density
Specific Heat Capacity
Resistance
Asia
Africa
Europe
Others
North America
South America
Australia
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
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Durable Rock, Medium Hardness Rock
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Decorative Aggregates, Interior Decoration
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Creating Artwork, Mirror, Used in aquariums
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Blocks negativity, Helps to protect against depression
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.
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Erosion, Coastal Erosion, Glacier Erosion
Heat Resistant, Impact Resistant
Afghanistan, Indonesia, Japan, Russia
Greece, Hungary, Iceland, Italy, Turkey
Argentina, Chile, Ecuador, Peru
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Black, Brown, Pink, Red, White
Countertops, Decorative Aggregates, Flooring, Interior Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Generally rough to touch, Is one of the oldest rock
Konark Sun Temple in India, Washington Monument, US
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Biological Weathering, Mechanical Weathering
Chemical Erosion, Coastal Erosion, Sea Erosion
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
New South Wales, New Zealand, Queensland, Victoria