Definition
Jasperoid is a rare, peculiar type of metasomatic alteration of rocks
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
History
Origin
USA
New Zealand
Discoverer
Unknown
Unknown
Etymology
From silica, the main mineral content of Jasperoid
From German which means hornstone
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy
Granular, Platy
Color
Black, Brown, Green, Grey, Pink, White
Brown, Dark Greenish - Grey, Green, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Glassy or Pearly
Dull
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
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
for Road Aggregate, Roadstone
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Jewellery, Monuments, Sculpture
Artifacts, Monuments
Other Uses
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
-
Biotite hornfels
Features
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits
Smooth to touch
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.
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.
Composition
Mineral Content
Clay Minerals, Pyrite, Quartz, Sulfides
Andalusite
Compound Content
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
Fe, Mg
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
-
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
3.5-42-3
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
White
-
Porosity
Less Porous
Highly Porous
Luster
Vitreous and Pearly
Shiny
Compressive Strength
140.00 N/mm25.80 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
Perfect
Toughness
1
-
Specific Gravity
2.8-33.4-3.9
0
8.4
👆🏻
Transparency
Transparent to Translucent
Opaque
Density
2.8-2.9 g/cm30.25-0.30 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
Morocco, Namibia
Cameroon, East Africa, Tanzania, Western Africa
Europe
Austria, Italy, Romania, Spain, Switzerland
United Kingdom
Others
-
-
Deposits in Western Continents
North America
Mexico, USA
Canada, USA
South America
Brazil, Colombia
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Yorke Peninsula
New South Wales, New Zealand, Queensland, Western Australia