Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Origin
Iceland
Hawaii Islands
Discoverer
Unknown
Unknown
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
From Greek pikros bitter + -ite, 19th century
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Vitreous
Earthy, Rough
Color
Black, Dark Brown
Black, Brown, Green, Grey, Pink, White, Yellow
Durability
Durable
Durable
Appearance
Glassy
Rough and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
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.
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Types
Volcanic glass
Oceanite
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Host Rock for Lead
Archaeological Significance
Formation
Tachylite 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.
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
Feldspar, Olivine
Biotite, Olivine, Plagioclase, Pyrrhotite
Compound Content
Fe, Mg
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, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Uneven
Streak
Vermilion
White, Greenish White or Grey
Porosity
Less Porous
Less Porous
Luster
Resinous
Subvitreous to Dull
Specific Gravity
2.4
2.75-2.92
Transparency
Opaque
Opaque
Density
3.058 g/cm3
1.5-2.5 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Cambodia, Russia, South Korea
India, Russia
Africa
East Africa
South Africa
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
Iceland
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
All about Tachylite and Picrite Properties
Know all about Tachylite and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Tachylite and Picrite belong to Igneous Rocks.Texture of Tachylite is Vitreous whereas that of Picrite is Earthy, Rough. Tachylite appears Glassy and Picrite appears Rough and Shiny. The luster of Tachylite is resinous while that of Picrite is subvitreous to dull. Tachylite is available in black, dark brown colors whereas Picrite is available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Tachylite are cemetery markers, 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).