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
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
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
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Shiny
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
-
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
-
Surgery
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Jewellery
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
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.
Mineral Content
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
-
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
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium to Coarse Grained
-
Fracture
Irregular to Conchoidal
Conchoidal
Streak
White to Grey
White
Porosity
Less Porous
Very Less Porous
Luster
Vitreous to Dull
Vitreous
Specific Gravity
2.5
2.6-2.7
Transparency
Opaque
Translucent
Density
2.85-3.07 g/cm3
2.6 g/cm3
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
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
All about Amphibolite and Obsidian Properties
Know all about Amphibolite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Amphibolite belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks.Texture of Amphibolite is Banded, Foliated, Massive whereas that of Obsidian is Glassy. Amphibolite appears Foliated and Obsidian appears Shiny. The luster of Amphibolite is vitreous to dull while that of Obsidian is vitreous. Amphibolite is available in black, brown, green, grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Amphibolite are cemetery markers, commemorative tablets, creating artwork and that of Obsidian are creating artwork, mirror, used in aquariums.