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
Granophyre is a type of granitic rock which consists of intergrown feldspar and quartz crystals in a medium to fine grained groundmass
History
Origin
New Zealand
-
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From German Granophyr, from Granit granite + Porphyr
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Granular, Platy
Granophyric
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Grey, Orange, Pink, White
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull
Veined or Pebbled
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Bridges, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
-
Industry
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Curling, Gemstone, Laboratory bench tops, Tombstones
Types
Biotite hornfels
Intermediate intrusive rock
Features
Smooth to touch
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
Granophyre is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Composition
Mineral Content
Andalusite
Hornblade, Orthoclase, Plagioclase, Quartz
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Glacier Erosion, Sea Erosion, Wind Erosion
Physical Properties
Hardness
2-36-7
1
7
👆🏻
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
-
Streak
-
White
Porosity
Highly Porous
Less Porous
Luster
Shiny
Dull to Grainy with Sporadic parts Pearly and Vitreous
Compressive Strength
5.80 N/mm2175.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
-
-
Specific Gravity
3.4-3.92.6-2.7
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm32.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.79 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Cameroon, East Africa, Tanzania, Western Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
United Kingdom
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic
Others
-
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
-
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
-