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
Oil Shale is a fine-grained sedimentary rock from which oil is extracted
Origin
New Zealand
Unknown
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From Old English scealu in its base sense of thing that divides or separate
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular, Platy
Splintery
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Brown, Buff, Green, Grey, Red, Yellow
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Not Yet Used
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Not Yet Used
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
for Road Aggregate, Roadstone
Cement Manufacture, Construction Aggregate, for Road Aggregate, Serves as an Oil and Gas Reservoir rock
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
An Oil and Gas Reservoir
Types
Biotite hornfels
Carbonate-rich Shale, Siliceous Shale and Cannel Shale
Features
Smooth to touch
Easily splits into thin plates, Generally rough to touch, Is one of the oldest rock, Very fine grained 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.
Oil Shale forms on the beds of seas and lakes and its formation starts with the organic debris settling and accumulating at the bottom of a lake or sea which are then transformed into rock with the help of high temperature and pressure.
Mineral Content
Andalusite
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Compound Content
Fe, Mg
Ca, Fe, Mg, Silicon Dioxide, Sodium
Types of Metamorphism
Not Applicable
Not Applicable
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, Sea Erosion, Water Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Not Available
Porosity
Highly Porous
Highly Porous
Compressive Strength
Not Available
Toughness
Not Yet Found
2.6
Specific Gravity
3.4-3.9
2.2-2.8
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
2.4-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Bangladesh, China, India, Israel, Jordan, Russia, Syria, Thailand, Turkey
Africa
Cameroon, East Africa, Tanzania, Western Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Sweden, Switzerland
Others
Not Yet Found
Greenland, Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
Hornfels vs Oil shale 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 Oil shale characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Oil shale. Learn more about Hornfels vs Oil shale in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Oil shale include Not yet used. Due to some exceptional properties of Hornfels and Oil shale, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Oil shale include Cement manufacture, Construction aggregate, For road aggregate, Serves as an oil and gas reservoir rock.
More about Hornfels and Oil shale
Here you can know more about Hornfels and Oil shale. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Oil shale consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Oil shale includes Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Oil shale, 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, Oil shale is available in black, brown, buff, green, grey, red, yellow colors. Appearance of Hornfels is Dull and that of Oil shale is Muddy. Properties of rock is another aspect for Hornfels vs Oil shale. Hardness of Hornfels and Oil shale is 2-3. The types of Hornfels are Biotite hornfels whereas types of Oil shale are Carbonate-rich Shale, Siliceous Shale and Cannel Shale. 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 Oil shale is white. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Oil shale is 0.39 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 Oil shale is heat resistant, impact resistant.
