Definition
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
Harzburgite is a plutonic rock of the peridotite group consisting largely of orthopyroxene and olivine
Origin
New Zealand
Germany
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From the name of a town in Harzburg, Germany
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Granular, Platy
Phaneritic
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Dark Greenish - Grey
Durability
Durable
Durable
Appearance
Dull
Rough and Shiny
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Cobblestones
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Types
Biotite hornfels
Ultramafic rock
Features
Smooth to touch
Constitutes upper part of the Earth's mantle, Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Formation
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.
Harzburgite 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.
Mineral Content
Andalusite
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Compound Content
Fe, Mg
Ca, Fe, Mg, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Types of Metamorphism
-
Impact Metamorphism
Types of Weathering
Biological Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Highly Porous
Less Porous
Specific Gravity
3.4-3.9
3-3.01
Transparency
Opaque
Translucent to Opaque
Density
0.25-0.30 g/cm3
3.1-3.4 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Japan, Oman
Africa
Cameroon, East Africa, Tanzania, Western Africa
South Africa
Europe
United Kingdom
France, Germany, Italy
Others
-
Hawaii Islands, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
-
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
-
Hornfels vs Harzburgite 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. Hornfels vs Harzburgite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Harzburgite. Learn more about Hornfels vs Harzburgite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Harzburgite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Hornfels and Harzburgite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Harzburgite include As dimension stone, Cobblestones.
More about Hornfels and Harzburgite
Here you can know more about Hornfels and Harzburgite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Harzburgite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Harzburgite includes Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Harzburgite, the texture, color and appearance plays an important role in determining the type of rock. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas, Harzburgite is available in dark greenish - grey colors. Appearance of Hornfels is Dull and that of Harzburgite is Rough and Shiny. Properties of rock is another aspect for Hornfels vs Harzburgite. The hardness of Hornfels is 2-3 and that of Harzburgite is 5.5-6. The types of Hornfels are Biotite hornfels whereas types of Harzburgite are Ultramafic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is while that of Harzburgite is white. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Harzburgite is 1.25 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Hornfels is heat resistant, impact resistant, pressure resistant whereas Harzburgite is heat resistant, pressure resistant, wear resistant.