In addition to being cut and polished, some gemstones are given other treatments to improve their appearance. Most often this is done to improve the colour or the clarity of a stone. It is often difficult or impossible to tell with the naked eye whether or not a stone has been treated.
Some treatments, such as heating of sapphires and rubies, are widely accepted in the jewellery industry around the world. The vast majority of these stones – over 95% by some estimates – are heated to improve their colour. The change is permanent.
Other treatments are not as well accepted, for example where they mask a gemstone’s fragility.
At D.Hindley we only accept treatments that are permanent and do not affect the durability or weight of the stone. We do not sell any stones where the treatment is just to the surface.
We are always happy to answer any questions about gemstone treatments. The gemstone identification cards we obtain from independent labs for our higher value gemstones typically identify what treatment, if any, the stones have received.