Definition
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
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
Unknown
New Zealand
Discoverer
Unknown
Unknown
Etymology
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
From German which means hornstone
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic, Splintery
Granular, Platy
Color
Black, Brown, Buff, Green, Grey, Red, Yellow
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
for Road Aggregate, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments
Commercial Uses
Creating Artwork, Pottery
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Biotite hornfels
Features
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Smooth to touch
Archaeological Significance
Famous Monuments
Jantar Mantar in India
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
Formation
Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.
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
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Andalusite
Compound Content
Ca, Fe, Mg, Silicon Dioxide, Sodium
Fe, Mg
Types of Metamorphism
Not Applicable
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Not Available
Conchoidal
Porosity
Highly Porous
Highly Porous
Toughness
2.6
Not Yet Found
Specific Gravity
2.2-2.8
3.4-3.9
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Cameroon, East Africa, Tanzania, Western Africa
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
New South Wales, New Zealand, Queensland, Western Australia
All about Shale and Hornfels Properties
Know all about Shale and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Shale belongs to Sedimentary Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Shale is Clastic, Splintery whereas that of Hornfels is Granular, Platy. Shale appears Muddy and Hornfels appears Dull. The luster of Shale is dull while that of Hornfels is shiny. Shale is available in black, brown, buff, green, grey, red, yellow colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Shale are creating artwork, pottery and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.