The Elite Corundum Family

The Corundum family of gemstones is a very special one indeed as it makes up half of the elite group of jewels that can truly be called precious, Ruby and Sapphire join the diamond and emerald to conclude this unique set.

This families composition is aluminium oxide and the striking hard stones that it gives us are only surpassed by the diamond.

Ruby... is the red variety of aluminium oxide and literally gets it's name from the latin word meaning red.

Rubies come in colours ranging from a light pink to the deep blood red that are the most sought after.

They can be found in North Carolina within the United States but the best sources are in Myanmar (used to be Burma) this variety are known as pigeon's blood rubies, Sri Lanka which are a lighter red, Australia, Cambodia, Kenya as well as Pakistan, india and Madagascar.

Imperfections are very common in these gemstones as well as the inclusion of needles called 'silk' by the gem trade, also frequent twinning of the crystals can make them brittle even though they have a hardness of 9 on the Moh scale.

Spinel is often found near or even in the same rock as Ruby and sometimes is mistaken for the great red gem.

Inclusion of chromium will determine on how red the stone will be with a very rich dark red natural untreated specimen commanding a very high price.

Just like diamonds cut, carat and clarity all have important bearings into how the gemstone is priced.

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Sapphire... the other half of the Corundum family of gemstones comes in many different colours depending on the amount of titanium and iron impurities present, red varieties as you know are rubies and a pink orange Sapphire is known as a Padparadscha.

A clear deep blue is the most sought after colour with any other variety known as fancy Sapphires, in very rare circumstances clear and colourless stones have been found.

Some specimens called colour changing Sapphires shift between different shades of blue when viewed in natural or artificial lighting.

Sapphires are found in Montana within the United States offering a metallic blue coloured stone but generally the best blue gems originate from Sri Lanka, Africa, Australia, Brazil and Myanmar along with Pakistan,Thailand and Madagascar.

The best examples of Padparadscha come from Sri Lanka.

Just like the Ruby rutile needle inclusions in Sapphires is common and the 'silk' can give a star effect when viewing under a single light source.

Other impurities that are common in Sapphire are cracks and pits as well as tiny specs that look like dots of liquid.

Because of the stones lovely colours and hardness occasionally it will be cut into sheets and used as the face covering on expensive designer watches.

Madagascar Gems sells quality gem stone rough. We mine, export, and sell gem stone facet rough through our offices in Madagascar and Arizona... http://madagascar-gems.com

© Photographer:Marc Dietrich | Agency: Dreamstime.com

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