Corundum

Gemstone :

Corundum

Sapphire and Ruby make up the Corundum family.

Birthstone Month :

Sapphire is the birthstone for the month of September.

Ruby is the birthstone for the month of July.

Zodiac :

Sapphire is associated with the zodiac signs of Aries, Cancer, Libra, and Taurus.

Ruby is associated with the zodiac signs of Cancer, Leo, Sagittarius and Scorpio.

Chemical Symbol :

Al2O3

Chemical Make-up :

Corundum is an Aluminum Oxide. Pure Corundum is in fact clear, and Blue Corundum, or Sapphire, is made up of Corundum (Al2O3), and Iron & Titianium impurities (Fe2+ & Ti4+), which are responsible for the Blue coloration. Sapphire can also be found in every other color of the spectrum except red, with different trace impurities accounting for the coloration. Red Corundum, or Ruby, is made up of Corundum (Al2O3), and Chromiumium impurities (Cr3+), which are responsible for the wonderful

Red colorations. Ruby is the most valuable gem in the Corundum family

History & Lore :

The name Corundum is believed to originate from either the Indian word kauruntaka, or the Sanskrit word kurivinda. Sapphire, the name for this particular type of Corundum is taken from the Latin word sapphirus, meaning “blue”. Ruby, the name for this particular type of Corundum is taken from the Latin word ruber, meaning “red”.

Both Sapphire and Ruby have their own unique and interesting History & Lore. Please refer to their respective educations for further information.

Availability :

It is an extremely hard and a very expensive exercise trying to source natural Sapphires / Rubies that have not been heat-treated as these gems are amongst the most valuable gemstones known today. However, thanks to modern gemstone enhancements and treatments, it is now possible to own wonderful, heat-treated natural Sapphires/Rubies that are both available to meet demand, and priced at a level making this beautiful gemstone attainable / available to most people.

Sources :

Both Sapphire and Ruby have their own unique Sources. Please refer to their respective educations for further information.

Evaluation :

Corundum is rated at 9 on the Moh's Scale of Hardness and is second only to the Diamond in this regard. Corundum is perfectly suited to all jewelry purposes / uses, and is very hard-wearing, durable, versatile, and suitable for everyday wear.

Both Sapphire and Ruby have their own unique Evaluation. Please refer to their respective educations for further information.

Common Cuts :

Corundums are very well-suited to jewelry purposes, and Sapphires / Rubies are cut into almost all of the known gemstone cuts, with Cushion, Emerald, Pear and Oval cuts being particularly popular

Routine Enhancements :

Almost all Corundum found on the market today has been heat-treated in order to intensify coloration and remove “silk”, small inclusions present in most natural Sapphires / Rubies. This method of treatment is considered permanent and color should not fade over time.

Care & Cleaning :

Sapphires / Rubies are a very tough, durable gemstone and can safely be cleaned with soapy water or commercial solvent and a brush, and can also safely be cleaned using most modern mechanical cleaners. Do however avoid subjecting Sapphires / Rubies to prolonged exposure to strong heat or light sources, particularly with regard to heat- treated gems, as prolonged exposure may cause permanent changes in coloration. Sapphire/Ruby jewelry should always be stored in a fabric-lined box away from other jewelry items to avoid damage / scratching.