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
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
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
Durability
Durable
Durable
Appearance
Dull and Soft
Dull
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
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
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
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
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.
Mineral Content
Olivine, Plagioclase, Pyroxene
Andalusite
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
Fe, Mg
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
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
Specific Heat Capacity
Not Available
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
All about Adakite and Hornfels Properties
Know all about Adakite and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Adakite belongs to Igneous Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Adakite is Porphyritic whereas that of Hornfels is Granular, Platy. Adakite appears Dull and Soft and Hornfels appears Dull. The luster of Adakite is grainy, pearly and vitreous while that of Hornfels is shiny. Adakite is available in black, brown, light to dark grey colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Adakite are commemorative tablets, pottery, used in aquariums and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.