Corundum (sapphire) with diamonds in a platinum ring D.53232 Click to enlarge image
Corundum (sapphire) with diamonds in a platinum ring. Sri Lanka, Sapphire 33.39 carats, 25 mm. Registered 2004. D.53232. Image: Stuart Humphreys
© Australian Museum

Sapphire (aluminium oxide) can be many colours, but the beautiful blue we see most often is from traces of iron and titanium. This sapphire has been cut for maximum size and is quite shallow. Corundum (sapphire) is 9 on Mohs 10-point scale of hardness. Only diamond is harder.

Specimen details

  • Origin

    Sri Lanka

  • Size

    Sapphire 33.39 carats, 25 mm

  • Date

    Registered 2004

  • Collection number


One of our regular elderly Museum visitors, Mireille Gerardy, had a great appreciation for gemstones. We used to see her admiring the gems displayed in our former gem vault in the Planet of Minerals exhibition. We had not seen her for a long time when, in 2004, we were contacted by her solicitor. We were informed that she had unfortunately passed away but that she had bequeathed the Museum her sapphire ring. Her solicitor personally handed it over.

We were expecting a nice ring, but the Collection Manager, Ross Pogson, gasped and almost fell off his chair when he opened the jewellery box and saw an enormous sapphire of beautiful pale blue, surrounded by many diamonds in a platinum setting. The sapphire is undoubtedly from Sri Lanka and is 25 mm long. It was estimated at 33.39 carats. The style suggests the ring was made in the 1930s or 40s.

Glass models of diamonds
Sparkling glass models (from left to right) of the world’s largest and most famous cut diamonds, the Orloff diamond, the Koh-I-Noor diamond after it was re-cut to increase its brilliance, and the Koh-I-Noor before re-cutting, purchased in 1900 from the Mont de Piete, Pawnbroking Co., Sydney. Image: Stuart Humphreys
© Australian Museum

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