Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Origin
Iceland
New Zealand
Discoverer
Unknown
Ferdinand von Hochstetter
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
From the name of Dun Mountain, New Zealand, + -ite1
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, Opaque Rock
Texture
Vitreous
Phaneritic
Color
Black, Dark Brown
Dark Greenish - Grey
Durability
Durable
Durable
Appearance
Glassy
Rough and Shiny
Interior Uses
Decorative Aggregates, 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
Cutting Tool, Knives, Landscaping, Scrapers
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch, NA
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Figurines
Not Yet Used
Used
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.
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Mineral Content
Feldspar, Olivine
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Compound Content
Fe, Mg
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Medium to Fine Coarse Grained
Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Less Porous
Less Porous
Cleavage
Not Available
Imperfect
Toughness
Not Available
2.1
Specific Gravity
2.4
3-3.01
Transparency
Opaque
Translucent to Opaque
Density
3.058 g/cm3
2.84-2.85 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Cambodia, Russia, South Korea
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Africa
East Africa
Morocco, South Africa
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland, Venezuela
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Not Yet Found
Argentina, Brazil, Colombia, Ecuador, Venezuela
Deposits in Oceania Continent
Australia
Victoria
New Zealand, Western Australia