What are the similarities and differences between ruby and sapphire?

While you are shopping for jewellery, whether for yourself or for others, you may be wondering about the similarities and differences between a ruby and a sapphire. Both gemstones look beautiful, so how do they compare?

Luxury ruby and sapphire ring

Similarities:

1.Both a ruby and sapphire are made of the same mineral, corundum.

2.They have the same hardness, ranking 9 out of 10 on Mohs scale. The only gemstone harder is a diamond.

Differences:

1.Rubies contain chromium, which gives its red colour. More chromium would result in a more intense red colour. Pure corundum is colourless. The best rubies are the most expensive as compared to sapphires.

2.Rubies are rarer than sapphires, as they are usually found in Myanmar, the Himalayas mountains and Vietnam. Sapphires can be found in the same locations, as well as Africa and Australia.

3. Sapphires come in a wide range of colours, including blue, orange, pink and green. Iron and titanium results in blue sapphire.

Sapphires come in all colours

When purchasing ruby and sapphire jewellery, especially expensive ones, it is best to request for a gem report to certify the characteristics and cut. A gem certificate also would tell you whether the gem is natural or synthetic man-made. Higher quality rubies and sapphires with few inclusions and blemishes will be more valuable.

Bonus:

Sapphires and rubies could display a beautiful phenomenon called asterism, or a star effect. This 6-ray star pattern is caused by inclusions within the gemstone.

Beautiful ruby asterism

In addition, you could also come across colour-changing sapphires, where the colour changes based on different lightings. How interesting!

Colour change sapphire can appear different

Gem treatments:

Do note that while you are mesmerized by the beauty of rubies and sapphires, the gem could be treated to make it look more beautiful. Glass could be added as a filler for the cracks, to make the fractures less obvious. Remember to check with the retailer on whether the gem was treated, or ask for a gem report.

In addition, if you are buying an expensive piece of ruby jewellery (greater than SGD5,000/RM17,000, or even six figures, do request for a gem report to certify that the gem is natural and not man-made synthetics, and does not have treatment.

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