Definition
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
Origin
New Zealand
New Zealand
Discoverer
Ferdinand von Hochstetter
Unknown
Etymology
From the name of Dun Mountain, New Zealand, + -ite1
From German which means hornstone
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phaneritic
Granular, Platy
Color
Dark Greenish - Grey
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Appearance
Rough and Shiny
Dull
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
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
for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Dunite
Biotite hornfels
Features
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Smooth to touch
Archaeological Significance
Formation
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Andalusite
Compound Content
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Fe, Mg
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Less Porous
Highly Porous
Specific Gravity
3-3.01
3.4-3.9
Transparency
Translucent to Opaque
Opaque
Density
2.84-2.85 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
Morocco, South Africa
Cameroon, East Africa, Tanzania, Western Africa
Europe
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Argentina, Brazil, Colombia, Ecuador, Venezuela
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, New Zealand, Queensland, Western Australia