Corundum – Harry & Co Jewellery

General Information and Physical Properties of Corundum

Corundum is an oxide mineral belonging to the Hematite group.
Its chemical formula is represented by the repeating unit.
It is classified under the Strunz classification as 4.CB.05 and under the Dana classification as 4.3.1.1.
Corundum has a trigonal crystal system with a hexagonal scalenohedral crystal class.
It has a space group of R3c and a density of 4.02g/cm.
Corundum is a mineral composed of aluminum oxide.
It has a hardness of 9 on the Mohs scale, making it one of the hardest minerals.
Corundum can occur in a variety of colors, including red (ruby) and blue (sapphire).
It has a high refractive index, giving it excellent brilliance and luster.
Corundum is chemically inert and resistant to most chemicals.
Corundum crystallizes with trigonal symmetry in the space group R3c.
Its lattice parameters are a = 4.75 Å and c = 12.982 Å at standard conditions.
The unit cell of corundum contains six formula units.
The toughness of corundum is influenced by surface roughness and crystallographic orientation.
In the corundum lattice, oxygen atoms form a slightly distorted hexagonal close packing, with aluminum ions occupying two-thirds of the octahedral sites.
Corundum is the second hardest natural mineral after diamond.

Corundum has two primary gem varieties: ruby and sapphire.
Rubies are red due to the presence of chromium, while sapphires exhibit a range of colors depending on the transition metal present.
Padparadscha sapphire is a rare pink-orange variety of corundum.
The name 'corundum' is derived from the Tamil-Dravidian word 'kurundam' meaning ruby-sapphire.
Corundum is a naturally transparent material, but its color varies based on impurities in its crystalline structure.

Corundum is commonly used as an abrasive on sandpaper and large tools in metal, plastic, and wood machining.
Emery, a variety of corundum, is used as an abrasive and is mixed with magnetite, hematite, or hercynite.
Corundum is used in the production of mechanical parts, scratch-resistant optics, watch crystals, and instrument windows for satellites and spacecraft.
It is also utilized in the manufacture of laser components and ceramic armor due to its high hardness.
The gravitational wave detectors KAGRA and Advanced LIGO use sapphire mirrors made from corundum.
Corundum is widely used as an abrasive due to its hardness.
It is used in the production of grinding wheels, sandpaper, and polishing compounds.
Corundum is also used in the manufacturing of refractory materials, such as bricks and crucibles.
It is a key component in the production of synthetic sapphires for various applications.
Corundum is used in the electronics industry for making insulating substrates.

Corundum is used as a component in armor plating due to its high hardness and toughness.
It is used in the production of cutting tools, such as drill bits and saw blades.
Corundum is used in the manufacturing of high-temperature resistant ceramics.
It is used as a catalyst support in various chemical processes.
Corundum is used in the production of specialized lenses and windows for optical devices.
Corundum is used in the construction of mirrors for gravitational wave detectors.
It is used in the production of core optics components for advanced laser interferometers.
Corundum is used in the development of high-performance ceramic materials.

Corundum occurs in mica schist, gneiss, marbles, and low-silica igneous rocks like syenite and nepheline syenite.
It can be found adjacent to ultramafic intrusives, lamprophyre dikes, and as large crystals in pegmatites.
Corundum is commonly found in stream and beach sands as a detrital mineral due to its hardness and resistance to weathering.
Major corundum deposits are mined in countries like Zimbabwe, Pakistan, Afghanistan, Russia, Sri Lanka, and India.
Synthetic corundum is produced using various methods and is available on the market at a lower cost than natural stones.
Corundum has been used in jewelry for centuries and is highly valued for its beauty and durability.
The largest corundum crystal ever found weighed over 250 kilograms.
Corundum is often found in metamorphic rocks, such as marble and schist.
Synthetic corundum can be created through various processes, including flame fusion and flux growth.
Corundum has been used in the study of crystallography, fracture mechanics, and material strength.

Reference	URL
Glossary	https://harryandcojewellery.com.au/blogs/glossary/corundum
Wikipedia	http://en.wikipedia.org/wiki/Corundum
Wikidata	https://www.wikidata.org/wiki/Q131777
Knowledge Graph	https://www.google.com/search?kgmid=/m/01stq