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
  
Dolomite is a sedimentary rock containing more than 50 percent of the mineral dolomite by weight
  
History
  
  
Origin
New Zealand
  
Southern Alps, France
  
Discoverer
Unknown
  
Dolomieu
  
Etymology
From German which means hornstone
  
From French, from the name of Dolomieu (1750–1801), the French geologist who discovered the rock
  
Class
Metamorphic Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Granular, Platy
  
Earthy
  
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
  
Black, Brown, Colourless, Green, Grey, Pink, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
No
  
Appearance
Dull
  
Glassy or Pearly
  
Architecture
  
  
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
  
Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Not Yet Used
  
Industry
  
  
Construction Industry
for Road Aggregate, Roadstone
  
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock
  
Medical Industry
Not Yet Used
  
Taken as a Supplement for Calcium or Magnesium
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts, Jewellery, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
  
Types
Biotite hornfels
  
Boninite and Jasperoid
  
Features
Smooth to touch
  
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Present
  
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.
  
Dolomite rocks are originally deposited as calcite or aragonite rich limestone, but during diagenesis process, the calcite or aragonite is transformed into dolomite.
  
Composition
  
  
Mineral Content
Andalusite
  
Clay Minerals, Pyrite, Quartz, Sulfides
  
Compound Content
Fe, Mg
  
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Weathering
Yes
  
No
  
Types of Weathering
Biological Weathering
  
Not Applicable
  
Erosion
Yes
  
No
  
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Not Applicable
  
Physical Properties
  
  
Hardness
2-3
  
3.5-4
  
Grain Size
Fine Grained
  
Medium to Fine Coarse Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Unknown
  
White
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Shiny
  
Vitreous and Pearly
  
Compressive Strength
140.00 N/mm2
  
15
Cleavage
Perfect
  
Perfect
  
Toughness
Not Yet Found
  
1
  
Specific Gravity
3.4-3.9
  
2.8-3
  
Transparency
Opaque
  
Transparent to Translucent
  
Density
0.25-0.30 g/cm3
  
2.8-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.84 kJ/Kg K
  
15
0.92 kJ/Kg K
  
10
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
  
China, India
  
Africa
Cameroon, East Africa, Tanzania, Western Africa
  
Morocco, Namibia
  
Europe
United Kingdom
  
Austria, Italy, Romania, Spain, Switzerland
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Mexico, USA
  
South America
Bolivia, Brazil, Colombia, Ecuador
  
Brazil, Colombia
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand, Queensland, Western Australia
  
New South Wales, Queensland, Yorke Peninsula