Definition
Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture
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
Tonale, Italy
New Zealand
Discoverer
Warren Hamilton
Unknown
Etymology
From Tonale Pass, northern Italy, + -ite1
From Greek mulōn mill + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phaneritic
Foliated
Color
Black, Brown, Light to Dark Grey, White
Black to Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Banded and Foilated
Dull, Banded and Foilated
Architecture
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
for Road Aggregate, Landscaping, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone, Jewelry
Types
Dacite
Blastomylonites, Ultramylonites and Phyllonites
Features
Is one of the oldest rock, Typically speckled black and white.
Surfaces are often shiny
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes tonalite with quartz as major mineral.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Composition
Mineral Content
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Porphyroblasts
Compound Content
NaCl, CaO, MgO, Silicon Dioxide
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Physical Properties
Hardness
6-73-4
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Shiny
Compressive Strength
185.00 N/mm21.28 N/mm2
0.15
450
👆🏻
Cleavage
-
Conchoidal
Toughness
2.1
-
Specific Gravity
2.86-32.97-3.05
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.73 g/cm32.6-4.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K1.50 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Water Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
-
China, India, Indonesia, Saudi Arabia, South Korea
Africa
Egypt
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Finland, Germany, Italy, Romania, Sweden, Turkey
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Others
-
-
Deposits in Western Continents
North America
USA
USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
-
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, Western Australia