Definition
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
  
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
  
History
  
  
Origin
Unknown
  
Ethiopia
  
Discoverer
Alexandre Brongniart
  
Obsius
  
Etymology
From Amphibole + -ite
  
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
  
Opaque Rock
  
Texture
Banded, Foliated, Massive
  
Glassy
  
Color
Black, Brown, Green, Grey
  
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Foliated
  
Shiny
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
  
Garden Decoration
  
Other Architectural Uses
Curbing
  
Not Yet Used
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
  
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
  
Medical Industry
Not Yet Used
  
Surgery
  
Antiquity Uses
Artifacts, Sculpture, Small Figurines
  
Artifacts, Jewellery
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Creating Artwork, Mirror, Used in aquariums
  
Types
Hornblendite
  
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
  
Features
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
  
Blocks negativity, Helps to protect against depression
  
Archaeological Significance
  
  
Monuments
Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.
  
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.
  
Composition
  
  
Mineral Content
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
  
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
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
6-7
  
5-5.5
  
Grain Size
Medium to Coarse Grained
  
Not Applicable
  
Fracture
Irregular to Conchoidal
  
Conchoidal
  
Streak
White to Grey
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Vitreous to Dull
  
Vitreous
  
Compressive Strength
Not Available
  
Cleavage
Irregular
  
Non-Existent
  
Toughness
2.3
  
Not Available
  
Specific Gravity
2.5
  
2.6-2.7
  
Transparency
Opaque
  
Translucent
  
Density
2.85-3.07 g/cm3
  
2.6 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
Russia, Turkey
  
Afghanistan, Indonesia, Japan, Russia
  
Africa
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
  
Kenya
  
Europe
Germany, Greece, Iceland, Norway, Poland
  
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
South Australia, Western Australia
  
New Zealand