Definition
Definition
Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
History
Origin
Southern Alps, France
New Zealand
Discoverer
Jakob Sederholm
Unknown
Etymology
From the Greek word migma which means a mixture
From Greek mulōn mill + -ite
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
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Texture
Foliated
Foliated
Color
Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black
Black to Grey
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Dull, Banded and Foilated
Uses
Architecture
Interior Uses
Countertops, Flooring, Kitchens
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
for Road Aggregate, Landscaping, Roadstone
Medical Industry
Not Available
Not Available
Antiquity Uses
Artifacts
Artifacts, Monuments
Other Uses
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends
Creating Artwork, Gemstone, Jewelry
Types
Types
Diatexites and Metatexites
Blastomylonites, Ultramylonites and Phyllonites
Features
Generally rough to touch, Is one of the oldest rock
Surfaces are often shiny
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Not Available
Pictographs
Used
Used
Petroglyphs
Used
Used
Figurines
Not Yet Used
Used
Fossils
Absent
Absent
Formation
Formation
Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Composition
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Porphyroblasts
Compound Content
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Not Applicable
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Properties
Physical Properties
Hardness
5.5-6.53-4
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Streak
White
White
Porosity
Very Less Porous
Highly Porous
Luster
Dull to Pearly to Subvitreous
Shiny
Compressive Strength
NA1.28 N/mm2
0.15
450
👆🏻
Cleavage
Not Available
Conchoidal
Toughness
1.2
Not Available
Specific Gravity
2.65-2.752.97-3.05
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
Not Available2.6-4.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
NA1.50 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Reserves
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
China, India, Indonesia, Saudi Arabia, South Korea
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Others
Not Available
Not Available
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Not Available
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria
Central Australia, Western Australia