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
Taconite is a low-grade iron ore which belongs to sedimentary rock and containing about 27% iron and 51% silica
Origin
New Zealand
Western Australia, Minnesota
Discoverer
Unknown
Newton Horace Winchell
Etymology
From German which means hornstone
From the name of Taconic Mountains in New England
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Not Applicable
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
Durability
Durable
Durable
Appearance
Dull
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
As a touchstone, Cemetery Markers, Creating Artwork
Types
Biotite hornfels
Not Available
Features
Smooth to touch
Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
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.
Taconite is a type of sedimentary rock formed when a river carries or transports pieces of broken rock as it flows. When the river reaches a lake or sea, its load of transported rocks settles or deposits at the bottom of sea or lake.
Mineral Content
Andalusite
Hematite, Magnetite, Quartz
Compound Content
Fe, Mg
Fe, Iron(III) Oxide, Silicon Dioxide
Types of Metamorphism
Not Applicable
Not Applicable
Types of Weathering
Biological Weathering
Biological Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Large and Coarse Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Highly Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Perfect
Imperfect
Toughness
Not Yet Found
1.5
Specific Gravity
3.4-3.9
5-5.3
Transparency
Opaque
Translucent to Opaque
Density
0.25-0.30 g/cm3
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact 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, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Cameroon, East Africa, Tanzania, Western Africa
Kenya, Morocco, South Africa, Tanzania
Europe
United Kingdom
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
New South Wales, Queensland, South Australia, Western Australia