Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.
Origin
New Zealand
Tonale, Italy
Discoverer
Ferdinand von Hochstetter
Unknown
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
Not Available
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Phaneritic
Phaneritic
Color
Dark Greenish - Grey
Black, Brown, Light to Dark Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Banded and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Cemetery Markers, Creating Artwork
Types
Not Available
Not Available
Features
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Is one of the oldest rock, Typically speckled black and white.
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Formation
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
NaCl, CaO, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Medium to Fine Coarse Grained
Fracture
Irregular
Conchoidal
Streak
White
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Shiny
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Imperfect
Not Available
Specific Gravity
3-3.01
2.86-3
Transparency
Translucent to Opaque
Opaque
Density
2.84-2.85 g/cm3
2.73 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Not Yet Found
Africa
Morocco, South Africa
Egypt
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland, Venezuela
Finland, Germany, Italy, Romania, Sweden, Turkey
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand, South Australia, Western Australia