Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Taconite is a low-grade iron ore which belongs to sedimentary rock and containing about 27% iron and 51% silica
History
Origin
New Zealand
Western Australia, Minnesota
Discoverer
Ferdinand von Hochstetter
Newton Horace Winchell
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
From the name of Taconic Mountains in New England
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Phaneritic
Banded, Trellis
Color
Dark Greenish - Grey
Red, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Shiny
Layered, Banded, Veined and Shiny
Architecture
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, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
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, Used for flooring, stair treads, borders and window sills.
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
As a touchstone, Cemetery Markers, Creating Artwork
Types
Dunite
Iron formation
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
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Taconite is a type of sedimentary rock formed when a river carries or transports pieces of broken rock as it flows. When the river reaches a lake or sea, its load of transported rocks settles or deposits at the bottom of sea or lake.
Composition
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Hematite, Magnetite, Quartz
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Fe, Iron(III) Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
3.5-45.5-6
1
7
👆🏻
Grain Size
Coarse Grained
Large and Coarse Grained
Fracture
Irregular
Uneven, Splintery or Conchoidal
Streak
White
White
Porosity
Less Porous
Highly Porous
Luster
Shiny
Earthy
Compressive Strength
107.55 N/mm2190.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
2.1
1.5
Specific Gravity
3-3.015-5.3
0
8.4
👆🏻
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.84-2.85 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.25 kJ/Kg K3.20 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Morocco, South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
-
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, Queensland, South Australia, Western Australia