Gem Treatments | First State Auctions

Gem Treatments

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BEWARE: Ruby Lead Glass Treatment
At First State Auctions, we will NEVER include Lead Glass treated rubies in our auctions.



The gemstone you see in a piece of fine jewellery almost never resembles the thing that came out of the ground. In fact, many when found are positively dull! This is why stones have been heat treated for centuries, to bring out the dominant colour and improve clarity – especially effective in precious gems such as rubies and sapphires.

Heat-treating has been accepted as a natural way to improve a gemstone’s appearance, even adding to its value through its favourable end result. With rubies, it is rare to find one in the market that hasn't been heat-treated. However, not all treatments are created equal…

Back in 2004, a sudden wave of impressive-looking rubies flooded the market. These were eventually traced back to gem gurus in Thailand, who had perfected a new method known as ‘Lead Glass Filling’. It’s exactly as it sounds, with low quality rubies having their cavities filled with lead glass. Because of the filling and the carat weight the perceived value is therefore greatly increased. However, lead glass is unstable, will deteriorate over time and this type of treatment is NOT accepted by the JAA (Jewellers Association of Australia) or the jewellery trade in general.



Buyer beware. While the carat weight may be identical, a ruby that has been heat treated will be worth 100 times more than an equivalent weight gem with lead glass filling. So, that could mean $10,000 versus $100 for a stone seemingly identical to the naked eye!
At First State Auctions, we will NEVER include Lead Glass treated rubies in our auctions. Our gemmological team carefully and specifically inspects every single ruby that comes through the door – our qualified experts guaranteeing every one of our descriptions.



Be aware that some businesses may declare a ruby to be ‘enhanced’. While this may mean heat treated, it could also be hiding something more sinister. And if they are not JAA members, you may find yourself out of pocket 100 times over!

For this reason (and many others), we always recommend purchasing your jewellery from a JAA member, such as First State Auctions. It’s an important investment – so make sure it’s right.