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
Dunite vs Hornfels 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. Dunite vs Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Dunite and Properties of Hornfels. Learn more about Dunite vs Hornfels in the next section. The interior uses of Dunite include Decorative aggregates and Interior decoration whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Dunite and Hornfels, they have various applications in construction industry. The uses of Dunite in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar and that of Hornfels include For road aggregate, Roadstone.
More about Dunite and Hornfels
Here you can know more about Dunite and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Dunite and Hornfels consists of mineral content and compound content. The mineral content of Dunite includes Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene and mineral content of Hornfels includes Andalusite. You can also check out the list of all Igneous Rocks. When we have to compare Dunite vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Dunite is available in dark greenish - grey colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Dunite is Rough and Shiny and that of Hornfels is Dull. Properties of rock is another aspect for Dunite vs Hornfels. The hardness of Dunite is 3.5-4 and that of Hornfels is 2-3. The types of Dunite are Dunite whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Dunite is white while that of Hornfels is . The specific heat capacity of Dunite is 1.25 kJ/Kg K and that of Hornfels is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Dunite is heat resistant, pressure resistant, wear resistant whereas Hornfels is heat resistant, impact resistant, pressure resistant.