Definition
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
  
Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components
  
History
  
  
Origin
New Zealand
  
Southern Alps, France
  
Discoverer
Unknown
  
Jakob Sederholm
  
Etymology
From Greek mulōn mill + -ite
  
From the Greek word migma which means a mixture
  
Class
Metamorphic Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Foliated
  
Foliated
  
Color
Black to Grey
  
Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
No
  
Appearance
Dull, Banded and Foilated
  
Dull, Banded and Foilated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Countertops, Flooring, Kitchens
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
  
As Building Stone, As Facing Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
for Road Aggregate, Landscaping, Roadstone
  
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone, Jewelry
  
Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends
  
Types
Blastomylonites, Ultramylonites and Phyllonites
  
Diatexites and Metatexites
  
Features
Surfaces are often shiny
  
Generally rough to touch, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
  
Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.
  
Composition
  
  
Mineral Content
Porphyroblasts
  
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
  
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
  
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
  
Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
3-4
  
5.5-6.5
  
Grain Size
Fine Grained
  
Medium to Fine Coarse Grained
  
Fracture
Conchoidal
  
Irregular
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Very Less Porous
  
Luster
Shiny
  
Dull to Pearly to Subvitreous
  
Compressive Strength
Not Available
  
Cleavage
Conchoidal
  
Poor
  
Toughness
Not Available
  
1.2
  
Specific Gravity
2.97-3.05
  
2.65-2.75
  
Transparency
Opaque
  
Opaque
  
Density
2.6-4.8 g/cm3
  
Not Available
  
Thermal Properties
  
  
Specific Heat Capacity
1.50 kJ/Kg K
  
3
Not Available
  
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Indonesia, Saudi Arabia, South Korea
  
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
  
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
  
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
  
Europe
England, Finland, France, Germany, Great Britain, Greece, 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
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
USA
  
Canada, Costa Rica, Cuba, Mexico, Panama, USA
  
South America
Not Yet Found
  
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Central Australia, Western Australia
  
New South Wales, New Zealand, Queensland, Victoria