Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Origin
Hawaii Islands
USA
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Quench
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
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.
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Creating Artwork, Gemstone
Types
Oceanite
Cataclastic rock
Features
Host Rock for Lead
Host Rock for Lead
Archaeological Significance
Formation
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
-
Grain Size
Fine Grained
Very fine-grained
Streak
White, Greenish White or Grey
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Vitreous
Specific Gravity
2.75-2.92
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
1.5-2.5 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Russia
South Korea
Africa
South Africa
Western Africa
Europe
Iceland
Great Britain, Switzerland
Deposits in Western Continents
North America
Canada, USA
-
Deposits in Oceania Continent
Australia
-
Central Australia, Western Australia
All about Picrite and Pseudotachylite Properties
Know all about Picrite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Picrite is Earthy, Rough whereas that of Pseudotachylite is Quench. Picrite appears Rough and Shiny and Pseudotachylite appears Dull and Soft. The luster of Picrite is subvitreous to dull while that of Pseudotachylite is vitreous. Picrite and Pseudotachylite are available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Pseudotachylite are creating artwork, gemstone.