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
Jaspillite is an iron rich chemically formed rock which is common in banded iron formation rocks
History
Origin
New Zealand
Western Australia, Minnesota
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From Jaspilite (Mineral), a compact siliceous rock which resembles jasper
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Granular, Platy
Banded, Trellis
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Red, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull
Banded and Glassy
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
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
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Jewellery, Monuments
Other Uses
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Jewelry
Types
Biotite hornfels
Algoma-type , Lake Superior-type and Superior-type
Features
Smooth to touch
Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
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.
Jaspillite is a type of sedimentary rock which is formed by the compaction and sedimentation of pieces of broken or weathered rocks and minerals.
Composition
Mineral Content
Andalusite
Coesite, Quartz, Sand
Compound Content
Fe, Mg
Fe, Iron(III) Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion
Physical Properties
Hardness
2-33
1
7
👆🏻
Grain Size
Fine Grained
Large and Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
-
White
Porosity
Highly Porous
Very Less Porous
Luster
Shiny
Earthy
Compressive Strength
5.80 N/mm2230.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
-
-
Specific Gravity
3.4-3.95.0-5.3
0
8.4
👆🏻
Transparency
Opaque
Translucent to Opaque
Density
0.25-0.30 g/cm30-5.7 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K3.20 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Russia
Africa
Cameroon, East Africa, Tanzania, Western Africa
-
Europe
United Kingdom
Ukraine
Others
-
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
Western Australia