|WHAT IS CORUNDUM MEANING
After the diamond corundum are the hardest gemstones, its hardness on the Mohs' scale is 9. From a chemical point of view corundum is aluminum oxide, various colors give it an admixture of chromium, iron, vanadium and other compounds. It is found in two varieties: common corundum, which is impure, coarse, opaque and granular (known as emery), and used as an abrasive; and transparent corundum, which includes the ruby and the sapphire (both identical except as to colour). The colours in some cases are probably due to traces of metallic oxides.
The term “ corundum ” probably comes from the Sanskrit word kurivinda or Indian kauruntaka.
Corundum (seldom colourless) exhibits a wide range of colours (blue, pink, green, yellow, etc.) and such stones are
properly termed sapphires preceded by the appropriate colour (designations using the names of other similar-appearing stones preceded by the word 'Oriental' being misnomers), except that the red variety is called 'ruby'.
In the jewelry market transparent corundum intense color traditionally have their own names.
The cut specimens are characterized by their vitreous lustre high specific gravity, weak colour dispersion, double refraction and, when coloured, dichroism, which enable them to be distinguished from other varieties of stones of similar appearance, as does microscopic examination.
Due to its hardness unjewelry corundum is known as abrasive materials. Not accidentally, the word "abrasive" is synonymous with old-corundum. According to one version, the biblical Moses carved his ten Commandments on the plates of lapis lazuli with fine-grained corundum.
There are green (hlorosapfiry) and colorless corundum (sapphire), as well as stones from the effect of a star (asterism). In the old days purple corundum called Bengal amethyst, a red-violet stones - almandine sapphires. Violet transparent corundum are known as Viola (Italian “viola” meaning “violet"). Transparent corundum orange shade called “padparadzha”, and yellowish-pink is “padparadshah”.
Often in the names of the various options corundum dealers and jewelers used the word "Oriental", which was to emphasize the quality of the stones. East diamond, east aquamarine stone, east emerald gem, east topaz or eastern beryl are the old names of corunds respective colors. Red corundum are known as ruby stone, blue - as sapphires .
Traditionally gem-quality corundum mined in Burma, Thailand, India (Kashmir), Madagascar and Sri Lanka. Known rocks from Kazakhstan, Canada, Norway, the United States, Russia.
Currently, the production of synthetic corundum put on an industrial basis. Often they are painted versions have their own names. Most of the synthesized corundum is used in the technique, only some of these stones are for the manufacture of inserts in jewelry.