Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Epidosite is a highly altered epidote and quartz bearing rock which is a type of metasomatite, essentially altered basalt
Discoverer
Unknown
Unknown
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
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Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Vitreous
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Dark Brown
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Glassy
Dull and Soft
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Commemorative Tablets, Creating Artwork
Types
Volcanic glass
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Has High structural resistance against erosion and climate, Very fine grained rock
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.
Epidosite 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
Olivine, Plagioclase, Pyroxene
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
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Grain Size
Medium to Fine Coarse Grained
Fine to Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
Vermilion
White to Grey
Porosity
Less Porous
Less Porous
Specific Gravity
2.4
2.8-3
Transparency
Opaque
Opaque
Density
3.058 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear 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
Tachylite vs Epidosite 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. Tachylite vs Epidosite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Tachylite and Properties of Epidosite. Learn more about Tachylite vs Epidosite in the next section. The interior uses of Tachylite include Decorative aggregates and Interior decoration whereas the interior uses of Epidosite include Decorative aggregates, Floor tiles, Homes, Hotels and Interior decoration. Due to some exceptional properties of Tachylite and Epidosite, they have various applications in construction industry. The uses of Tachylite in construction industry include Cutting tool, Knives, Landscaping, Scrapers and that of Epidosite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Tachylite and Epidosite
Here you can know more about Tachylite and Epidosite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Tachylite and Epidosite consists of mineral content and compound content. The mineral content of Tachylite includes Feldspar, Olivine and mineral content of Epidosite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Tachylite vs Epidosite, the texture, color and appearance plays an important role in determining the type of rock. Tachylite is available in black, dark brown colors whereas, Epidosite is available in black, brown, light to dark grey colors. Appearance of Tachylite is Glassy and that of Epidosite is Dull and Soft. Properties of rock is another aspect for Tachylite vs Epidosite. The hardness of Tachylite is 5.5 and that of Epidosite is 6. The types of Tachylite are Volcanic glass whereas types of Epidosite are Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Tachylite is vermilion while that of Epidosite is white to grey. The specific heat capacity of Tachylite is 0.56 kJ/Kg K and that of Epidosite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Tachylite is heat resistant, impact resistant, wear resistant whereas Epidosite is heat resistant, pressure resistant, wear resistant.