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
  
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
  
History
  
  
Origin
Adak, Aleutian Islands
  
New Zealand
  
Discoverer
Defant and Drummond
  
Unknown
  
Etymology
From Adak, Aleutian Islands
  
From German which means hornstone
  
Class
Igneous Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Granular, Platy
  
Color
Black, Brown, Light to Dark Grey
  
Brown, Dark Greenish - Grey, Green, Reddish Brown
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
No
  
Yes
  
Scratch Resistant
No
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Dull and Soft
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
  
Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Whetstones
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
for Road Aggregate, Roadstone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments
  
Other Uses
  
  
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
  
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Types
Not Available
  
Biotite hornfels
  
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
  
Smooth to touch
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
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
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.
  
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.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Andalusite
  
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
  
Fe, Mg
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Biological Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
  
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
3-4
  
2-3
  
Grain Size
Fine to Medium Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Bluish Black
  
Unknown
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Grainy, Pearly and Vitreous
  
Shiny
  
Compressive Strength
Not Available
  
Cleavage
Not Available
  
Perfect
  
Toughness
Not Available
  
Not Yet Found
  
Specific Gravity
Not Available
  
3.4-3.9
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
0.25-0.30 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.84 kJ/Kg K
  
15
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
  
Africa
Ethiopia, Somalia, South Africa
  
Cameroon, East Africa, Tanzania, Western Africa
  
Europe
Iceland
  
United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Bolivia, Brazil, Colombia, Ecuador
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New South Wales, New Zealand, Queensland, Western Australia
  
Adakite vs Hornfels 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. Adakite vs Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Adakite and Properties of Hornfels. Learn more about Adakite vs Hornfels in the next section. The interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Adakite and Hornfels, they have various applications in construction industry. The uses of Adakite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Hornfels include For road aggregate, Roadstone.
More about Adakite and Hornfels
Here you can know more about Adakite and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Adakite and Hornfels consists of mineral content and compound content. The mineral content of Adakite includes Olivine, Plagioclase, Pyroxene and mineral content of Hornfels includes Andalusite. You can also check out the list of all Igneous Rocks. When we have to compare Adakite vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Adakite is available in black, brown, light to dark grey colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Adakite is Dull and Soft and that of Hornfels is Dull. Properties of rock is another aspect for Adakite vs Hornfels. The hardness of Adakite is 3-4 and that of Hornfels is 2-3. The types of Adakite are Not Available whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Adakite is bluish black while that of Hornfels is unknown. The specific heat capacity of Adakite is Not Available and that of Hornfels is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Adakite is heat resistant, pressure resistant, wear resistant whereas Hornfels is heat resistant, impact resistant, pressure resistant.