What is heat treatment & why

Heat treating is the most common Sapphire treatment where a gem is heated to improve the clarity and remove silky deposits in the stone. The mildest form is heating the rough stone to around 400 degrees centigrade for brief periods of time.

In the last 30 years, much higher temperatures are used upwards or 1600 degrees and higher, to burn out silt and improve the saturation of colour, turning sometimes a dull and lifeless stone into a bright colourful gem.

While heat treatment is more than accepted within the jeweller industry without the need for disclosure, certified Sapphires with fine coloured, unheated, eye-clean and clarity properties will always be highly prized and more valuable.

We have both certified heated and unheated Sapphires our boutique shop in Paddington QLD, 


Other treatments

Beryllium heat treatment or irradiating of a stone have a stronger affect on colour and often produces intense orange, bright yellow or near red Sapphire colours, which are very rare if found in the nature.

Although radiation can occur naturally in the earth while Sapphires were formed, some for example yellow Sapphires which are irradiated can be unstable (meaning, the stone can loose colour very quickly) once exposed to UV light (sun).

Heat treatment of Australian Sapphires

Very large percentage of all Sapphires are heat treated and Aussies are no exception.

In the recent years, a fair amount of Australian rough (raw material before cutting) is exported into Thailand, where the stones are cut and in majority of cases, heat treated. Heat treatment is also performed in Australia, it is not frowned upon within the jewellery industry and it is and has been common for many years.

Because of the cost of certification (Gemstone Laboratory), we do not offer certificate with our Australian Sapphires, unless our clients request it and there is an extra cost involved.

Want to find out more?

We are here to explain everything you need to know before making a decision of purchasing a Sapphire. You are welcome to get in touch below or give us a call or visit our Paddington jewellery boutique, located in beautiful Brisbane. 


This blog was written by David, our founder and design consultant.

If you have any questions, we would love to hear from you. You can also book your design session with Louise.