Definition
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.
  
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
  
History
  
  
Origin
England
  
Egypt
  
Discoverer
Unknown
  
Unknown
  
Etymology
From gan′is-ter i.e a hard, close-grained siliceous stone, often forming the stratum which underlies a coal-seam
  
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Clastic, Granular, Rough
  
Porphyritic
  
Color
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
  
Black, Brown, Colourless, Green, Grey, Red, Rust, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Rough
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
  
Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
  
Construction Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
An Oil and Gas Reservoir, In aquifers, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones
  
Creating Artwork, Gemstone, Jewelry
  
Types
Not Available
  
Rhomb Porphyry
  
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
  
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Absent
  
Formation
Ganisters are formed by the destruction of easily weathered minerals mainly feldspar, within the surface horizon of soil by soil-forming processes.
  
Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.
  
Composition
  
  
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
  
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering
  
Biological Weathering, Chemical Weathering, Not Registered
  
Erosion
Yes
  
Yes
  
Types of Erosion
Water Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
6-7
  
6-7
  
Grain Size
Coarse or Fine
  
Fine Grained
  
Fracture
Splintery
  
Irregular
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Dull
  
Compressive Strength
95.00 N/mm
2
  
20
Not Available
  
Cleavage
Perfect
  
Imperfect
  
Toughness
2.6
  
1.7
  
Specific Gravity
2.2-2.8
  
2.5-4
  
Transparency
Opaque
  
Translucent to Opaque
  
Density
2.2-2.8 g/cm3
  
2.5-2.52 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
  
Africa
Namibia, Nigeria, South Africa
  
Egypt, Ethiopia, Ghana, South Africa
  
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
  
Others
Greenland
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, Cuba, Jamaica, USA
  
South America
Brazil
  
Bolivia, Brazil, Colombia, Ecuador, Paraguay
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand
  
New South Wales, New Zealand, Western Australia
  
Ganister vs Porphyry 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. Ganister vs Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Ganister and Properties of Porphyry. Learn more about Ganister vs Porphyry in the next section. The interior uses of Ganister include Decorative aggregates, Entryways, Flooring, Homes and Interior decoration whereas the interior uses of Porphyry include Decorative aggregates and Interior decoration. Due to some exceptional properties of Ganister and Porphyry, they have various applications in construction industry. The uses of Ganister in construction industry include Cement manufacture, Construction aggregate, For road aggregate, Production of glass and ceramics, Raw material for the manufacture of mortar and that of Porphyry include Construction aggregate.
More about Ganister and Porphyry
Here you can know more about Ganister and Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Ganister and Porphyry consists of mineral content and compound content. The mineral content of Ganister includes Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz and mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica. You can also check out the list of all Sedimentary Rocks. When we have to compare Ganister vs Porphyry, the texture, color and appearance plays an important role in determining the type of rock. Ganister is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors whereas, Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. Appearance of Ganister is Rough and that of Porphyry is Dull. Properties of rock is another aspect for Ganister vs Porphyry. Hardness of Ganister and Porphyry is 6-7. The types of Ganister are Not Available whereas types of Porphyry are Rhomb Porphyry. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Ganister and Porphyry is white. The specific heat capacity of Ganister is 0.92 kJ/Kg K and that of Porphyry is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Ganister is heat resistant, impact resistant, pressure resistant whereas Porphyry is heat resistant, impact resistant.