Definition
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Origin
North America
Hawaii Islands
Discoverer
Unknown
Unknown
Etymology
From Andes mountains, where it is found in abundance
From Greek pikros bitter + -ite, 19th century
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy, Rough
Color
Bluish - Grey, Grey, Pink, Yellow
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Rough and Shiny
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Office Buildings, Roof Tiles
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cobblestones, Construction Aggregate, for Road Aggregate
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Commemorative Tablets, Creating Artwork
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Types
Icelandite
Oceanite
Features
Generally rough to touch, High silica content, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
Middle of the Earth in Ecuador
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Formation
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Biotite, Olivine, Plagioclase, Pyrrhotite
Compound Content
Silicon Dioxide
Al, CaO, Carbon Dioxide, Mg, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Fine Grained
Streak
White
White, Greenish White or Grey
Porosity
Less Porous
Less Porous
Luster
Vitreous
Subvitreous to Dull
Cleavage
Not Available
Imperfect
Specific Gravity
2.5-2.8
2.75-2.92
Transparency
Opaque
Opaque
Density
2.11-2.36 g/cm3
1.5-2.5 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Indonesia, Japan, Nepal, South Korea
India, Russia
Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
South Africa
Europe
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Mexico, USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
Not Yet Found
All about Andesite and Picrite Properties
Know all about Andesite and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Andesite and Picrite belong to Igneous Rocks.Texture of Andesite is Aphanitic to Porphyritic whereas that of Picrite is Earthy, Rough. Andesite appears Dull and Soft and Picrite appears Rough and Shiny. The luster of Andesite is vitreous while that of Picrite is subvitreous to dull. Andesite is available in bluish - grey, grey, pink, yellow colors whereas Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors. The commercial uses of Andesite are commemorative tablets, creating artwork and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).