Definition
Anorthosite is a granular igneous rock composed largely of labradorite or 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
Unknown
Obsius
Etymology
From French anorthose plagioclase + -ite1
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
Coarse Grained Rock, Opaque Rock
Opaque Rock
Texture
Foliated, Glassy
Glassy
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Shiny
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration
Other Architectural Uses
Curbing
-
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Jewellery
Commercial Uses
Creating Artwork, Curling
Creating Artwork, Mirror, Used in aquariums
Types
Proterozoic Anorthosite and Archean Anorthosite
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Generally rough to touch, Is one of the oldest rock
Blocks negativity, Helps to protect against depression
Archaeological Significance
Formation
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
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, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
-
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
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
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Coarse Grained
-
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Very Less Porous
Luster
Pearly to Subvitreous
Vitreous
Specific Gravity
2.62-2.82
2.6-2.7
Transparency
Translucent
Translucent
Density
2.7-4 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
-
Afghanistan, Indonesia, Japan, Russia
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Canada
Canada, Mexico, USA
South America
Bolivia, Colombia
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
New Zealand
Anorthosite vs Obsidian Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Anorthosite vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Anorthosite and Properties of Obsidian. Learn more about Anorthosite vs Obsidian in the next section. The interior uses of Anorthosite include Decorative aggregates, Floor tiles, Homes and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Anorthosite and Obsidian, they have various applications in construction industry. The uses of Anorthosite in construction industry include As dimension stone, Cement manufacture, For road aggregate and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Anorthosite and Obsidian
Here you can know more about Anorthosite and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Anorthosite and Obsidian consists of mineral content and compound content. The mineral content of Anorthosite includes Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene and mineral content of Obsidian includes . You can also check out the list of all Igneous Rocks. When we have to compare Anorthosite vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Anorthosite is Layered, Banded, Veined and Shiny and that of Obsidian is Shiny. Properties of rock is another aspect for Anorthosite vs Obsidian. The hardness of Anorthosite is 5-6 and that of Obsidian is 5-5.5. The types of Anorthosite are Proterozoic Anorthosite and Archean Anorthosite whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Anorthosite and Obsidian is white. The specific heat capacity of Anorthosite is 0.84 kJ/Kg K and that of Obsidian is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Anorthosite is heat resistant, impact resistant, pressure resistant, scratch resistant, wear resistant whereas Obsidian is heat resistant, impact resistant.