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
Pyroxenite is a dark, greenish, granular intrusive igneous rock consisting mainly of pyroxenes and olivine
Origin
New Zealand
Unknown
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From pyro- fire + Greek xenos stranger as the mineral group was new to igneous rocks
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Not Applicable
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Granular, Platy
Clastic, Granular, Phaneritic, Porphyritic
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Durability
Durable
Durable
Appearance
Dull
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Biotite hornfels
Clinopyroxenites, Orthopyroxenites and Websterites
Features
Smooth to touch
Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Not Yet Used
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.
Pyroxenites are ultramafic igneous rocks which are made up of minerals of the pyroxene group, such as augite and diopside, hypersthene, bronzite or enstatite.
Mineral Content
Andalusite
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
Not Applicable
Burial Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Conchoidal
Uneven
Streak
Unknown
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Shiny
Dull to Vitreous to Submetallic
Compressive Strength
Not Available
Cleavage
Perfect
Irregular
Toughness
Not Yet Found
Not Available
Specific Gravity
3.4-3.9
3.2-3.5
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
3.1-3.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
India, Russia
Africa
Cameroon, East Africa, Tanzania, Western Africa
South Africa
Europe
United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
New Zealand, Queensland
Hornfels vs Pyroxenite 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 Pyroxenite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Pyroxenite. Learn more about Hornfels vs Pyroxenite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Pyroxenite include Countertops, Decorative aggregates, Interior decoration and Kitchens. Due to some exceptional properties of Hornfels and Pyroxenite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Pyroxenite include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Hornfels and Pyroxenite
Here you can know more about Hornfels and Pyroxenite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Pyroxenite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Pyroxenite includes Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Pyroxenite, 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, Pyroxenite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. Appearance of Hornfels is Dull and that of Pyroxenite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Hornfels vs Pyroxenite. The hardness of Hornfels is 2-3 and that of Pyroxenite is 7. The types of Hornfels are Biotite hornfels whereas types of Pyroxenite are Clinopyroxenites, Orthopyroxenites and Websterites. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is unknown while that of Pyroxenite is white, greenish white or grey. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Pyroxenite is Not Available. 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 Pyroxenite is impact resistant, pressure resistant, wear resistant.