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
Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components
Origin
New Zealand
Southern Alps, France
Discoverer
Unknown
Jakob Sederholm
Etymology
From German which means hornstone
From the Greek word migma which means a mixture
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Granular, Platy
Foliated
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black
Durability
Durable
Durable
Appearance
Dull
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Flooring, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends
Types
Biotite hornfels
Diatexites and Metatexites
Features
Smooth to touch
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
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.
Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.
Mineral Content
Andalusite
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Fe, Mg
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Highly Porous
Very Less Porous
Luster
Shiny
Dull to Pearly to Subvitreous
Specific Gravity
3.4-3.9
2.65-2.75
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Cameroon, East Africa, Tanzania, Western Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
United Kingdom
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
New South Wales, New Zealand, Queensland, Victoria
Hornfels vs Migmatite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Hornfels vs Migmatite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Migmatite. Learn more about Hornfels vs Migmatite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Migmatite include Countertops, Flooring and Kitchens. Due to some exceptional properties of Hornfels and Migmatite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Migmatite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Hornfels and Migmatite
Here you can know more about Hornfels and Migmatite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Migmatite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Migmatite includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Migmatite, the texture, color and appearance plays an important role in determining the type of rock. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas, Migmatite is available in black, bluish - grey, brown, brown- black, dark greenish - grey, dark grey to black colors. Appearance of Hornfels is Dull and that of Migmatite is Dull, Banded and Foilated. Properties of rock is another aspect for Hornfels vs Migmatite. The hardness of Hornfels is 2-3 and that of Migmatite is 5.5-6.5. The types of Hornfels are Biotite hornfels whereas types of Migmatite are Diatexites and Metatexites. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is while that of Migmatite is white. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Migmatite is 0.79 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Hornfels is heat resistant, impact resistant, pressure resistant whereas Migmatite is heat resistant, pressure resistant.