Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Origin
Hawaii Islands
Iceland
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From German Tachylite, from tachy- + Greek lutos soluble, melting
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy, Rough
Vitreous
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Black, Dark Brown
Durability
Durable
Durable
Appearance
Rough and Shiny
Glassy
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, 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
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.
Cutting Tool, Knives, Landscaping, Scrapers
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Cemetery Markers, Creating Artwork
Types
Oceanite
Volcanic glass
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Clasts are smooth to touch
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.
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.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Feldspar, Olivine
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Fe, Mg
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
Vermilion
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Resinous
Specific Gravity
2.75-2.92
2.4
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
3.058 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
Cambodia, Russia, South Korea
Africa
South Africa
East Africa
Europe
Iceland
England, Germany, Hungary, Iceland, Scotland, Sweden
Deposits in Western Continents
North America
Canada, USA
USA
Deposits in Oceania Continent
Picrite vs Tachylite 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. Picrite vs Tachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Picrite and Properties of Tachylite. Learn more about Picrite vs Tachylite in the next section. The interior uses of Picrite include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Tachylite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Picrite and Tachylite, they have various applications in construction industry. The uses of Picrite in construction industry include 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. and that of Tachylite include Cutting tool, Knives, Landscaping, Scrapers.
More about Picrite and Tachylite
Here you can know more about Picrite and Tachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Picrite and Tachylite consists of mineral content and compound content. The mineral content of Picrite includes Biotite, Olivine, Plagioclase, Pyrrhotite and mineral content of Tachylite includes Feldspar, Olivine. You can also check out the list of all Igneous Rocks. When we have to compare Picrite vs Tachylite, the texture, color and appearance plays an important role in determining the type of rock. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas, Tachylite is available in black, dark brown colors. Appearance of Picrite is Rough and Shiny and that of Tachylite is Glassy. Properties of rock is another aspect for Picrite vs Tachylite. The hardness of Picrite is 6.8 and that of Tachylite is 5.5. The types of Picrite are Oceanite whereas types of Tachylite are Volcanic glass. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Picrite is white, greenish white or grey while that of Tachylite is vermilion. The specific heat capacity of Picrite is 0.88 kJ/Kg K and that of Tachylite is 0.56 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Picrite is heat resistant whereas Tachylite is heat resistant, impact resistant, wear resistant.