Definition
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
  
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
  
History
  
  
Origin
Unknown
  
Adak, Aleutian Islands
  
Discoverer
Unknown
  
Defant and Drummond
  
Etymology
From English feldspar and -ite
  
From Adak, Aleutian Islands
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Volcanic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Arborescent Patterned, Vitreous
  
Porphyritic
  
Color
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
  
Black, Brown, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
No
  
Yes
  
Appearance
Layered, Banded, Veined and Shiny
  
Dull and Soft
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Flooring, Interior Decoration
  
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
  
Exterior Uses
Paving Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Office Buildings
  
Other Architectural Uses
Curbing
  
Whetstones
  
Industry
  
  
Construction Industry
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
  
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
Medical Industry
Surgery
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Mirror, Jewelry
  
Commemorative Tablets, Pottery, Used in aquariums
  
Types
Not Available
  
Not Available
  
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock
  
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Felsite 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.
  
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
  
Composition
  
  
Mineral Content
Feldspar, Iron Oxides
  
Olivine, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, MgO, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Glacier Erosion, Water Erosion
  
Coastal Erosion, Sea Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
5-5.5
  
3-4
  
Grain Size
Fine Grained
  
Fine to Medium Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White
  
Bluish Black
  
Porosity
Very Less Porous
  
Less Porous
  
Luster
Vitreous
  
Grainy, Pearly and Vitreous
  
Compressive Strength
Not Available
  
Cleavage
Non-Existent
  
Not Available
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
2.6-2.7
  
Not Available
  
Transparency
Translucent
  
Opaque
  
Density
2.6 g/cm3
  
Not Available
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Afghanistan, Indonesia, Japan, Russia
  
India, Russia
  
Africa
Kenya
  
Ethiopia, Somalia, South Africa
  
Europe
Greece, Hungary, Iceland, Italy, Turkey
  
Iceland
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, Mexico, USA
  
Canada, USA
  
South America
Argentina, Chile, Ecuador, Peru
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New Zealand
  
Not Yet Found
  
All about Felsite and Adakite Properties
Know all about Felsite and Adakite properties here. All properties of rocks are important as they define the type of rock and its application. Felsite and Adakite belong to Igneous Rocks.Texture of Felsite is Arborescent Patterned, Vitreous whereas that of Adakite is Porphyritic. Felsite appears Layered, Banded, Veined and Shiny and Adakite appears Dull and Soft. The luster of Felsite is vitreous while that of Adakite is grainy, pearly and vitreous. Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Adakite is available in black, brown, light to dark grey colors. The commercial uses of Felsite are mirror, jewelry and that of Adakite are commemorative tablets, pottery, used in aquariums.