Definition
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Origin
New Zealand
Iceland
Discoverer
Unknown
Unknown
Etymology
From Greek mulōn mill + -ite
From German Tachylite, from tachy- + Greek lutos soluble, melting
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated
Vitreous
Color
Black to Grey
Black, Dark Brown
Durability
Durable
Durable
Appearance
Dull, Banded and Foilated
Glassy
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Landscaping, Roadstone
Cutting Tool, Knives, Landscaping, Scrapers
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Creating Artwork
Types
Blastomylonites, Ultramylonites and Phyllonites
Not Available
Features
Surfaces are often shiny
Available in Lots of Colors and Patterns, Clasts are smooth to touch, NA
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
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
Porphyroblasts
Feldspar, Olivine
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Fe, Mg
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Cleavage
Conchoidal
Not Available
Toughness
Not Available
Not Available
Specific Gravity
2.97-3.05
2.4
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm3
3.058 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
Cambodia, Russia, South Korea
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
East Africa
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
England, Germany, Hungary, Iceland, Scotland, Sweden
Others
Not Yet Found
Hawaii Islands
Deposits in Western Continents
South America
Not Yet Found
Not Yet Found
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Victoria
Mylonite 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. Mylonite vs Tachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Mylonite and Properties of Tachylite. Learn more about Mylonite vs Tachylite in the next section. The interior uses of Mylonite include Decorative aggregates and Interior decoration whereas the interior uses of Tachylite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Mylonite and Tachylite, they have various applications in construction industry. The uses of Mylonite in construction industry include For road aggregate, Landscaping, Roadstone and that of Tachylite include Cutting tool, Knives, Landscaping, Scrapers.
More about Mylonite and Tachylite
Here you can know more about Mylonite and Tachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Mylonite and Tachylite consists of mineral content and compound content. The mineral content of Mylonite includes Porphyroblasts and mineral content of Tachylite includes Feldspar, Olivine. You can also check out the list of all Metamorphic Rocks. When we have to compare Mylonite vs Tachylite, the texture, color and appearance plays an important role in determining the type of rock. Mylonite is available in black to grey colors whereas, Tachylite is available in black, dark brown colors. Appearance of Mylonite is Dull, Banded and Foilated and that of Tachylite is Glassy. Properties of rock is another aspect for Mylonite vs Tachylite. The hardness of Mylonite is 3-4 and that of Tachylite is 5.5. The types of Mylonite are Blastomylonites, Ultramylonites and Phyllonites whereas types of Tachylite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Mylonite is white while that of Tachylite is vermilion. The specific heat capacity of Mylonite is 1.50 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.Mylonite is heat resistant, impact resistant, pressure resistant whereas Tachylite is heat resistant, impact resistant, wear resistant.
