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
A ganister is a hard, fine-grained quartzose sandstone or orthoquartzite which is basically used in the manufacture of silica brick typically used to line furnaces and is a type of sedimentary rocks.
History
Origin
Adak, Aleutian Islands
England
Discoverer
Defant and Drummond
Unknown
Etymology
From Adak, Aleutian Islands
From gan′is-ter i.e a hard, close-grained siliceous stone, often forming the stratum which underlies a coal-seam
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Clastic, Granular, Rough
Color
Black, Brown, Light to Dark Grey
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull and Soft
Rough
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Whetstones
Curbing
Industry
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
Medical Industry
-
-
Antiquity Uses
Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Commemorative Tablets, Pottery, Used in aquariums
An Oil and Gas Reservoir, In aquifers, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones
Types
Intermediate volcanic rock
Siliceous rock
Features
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
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.
Ganisters are formed by the destruction of easily weathered minerals mainly feldspar, within the surface horizon of soil by soil-forming processes.
Composition
Mineral Content
Olivine, Plagioclase, Pyroxene
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
Compound Content
Aluminium Oxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Water Erosion, Wind Erosion
Physical Properties
Hardness
3-46-7
1
7
👆🏻
Grain Size
Fine to Medium Grained
Coarse or Fine
Fracture
Conchoidal
Splintery
Streak
Bluish Black
White
Porosity
Less Porous
Highly Porous
Luster
Grainy, Pearly and Vitreous
Dull
Compressive Strength
200.00 N/mm295.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
-
2.6
Specific Gravity
-99992.2-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
-9999 g/cm32.2-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Ethiopia, Somalia, South Africa
Namibia, Nigeria, South Africa
Europe
Iceland
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
-
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand