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
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
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
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
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
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
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
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
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.
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
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Not Registered
Types of Erosion
Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Coarse or Fine
Fine Grained
Fracture
Splintery
Irregular
Porosity
Highly Porous
Less Porous
Compressive Strength
Not Available
Cleavage
Perfect
Imperfect
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
Specific Heat Capacity
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
All about Ganister and Porphyry Properties
Know all about Ganister and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Ganister belongs to Sedimentary Rocks while Porphyry belongs to Igneous Rocks.Texture of Ganister is Clastic, Granular, Rough whereas that of Porphyry is Porphyritic. Ganister appears Rough and Porphyry appears Dull. The luster of Ganister and Porphyry is dull. 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. The commercial uses of Ganister are an oil and gas reservoir, in aquifers, petroleum reservoirs, soil conditioner, source of magnesia (mgo), tombstones and that of Porphyry are creating artwork, gemstone, jewelry.