When coloured gemstones are used in jewellery, many of them will go through an enhancing process, including sapphires. The enhancement process can help alter the colour of the gem, making them much more vibrant, and they can also change the way they reflect and interact with light. Below are some enhancements techniques you can use with sapphires, so you know when shopping for jewellery some of the questions you may want to ask.
Heat Treatment For Sapphires
When you get 100% natural sapphires, they are almost colourless, and it is through heat treatment that the trace chemicals in the gems bring colour to them. However, there is no guarantee as to what colour the sapphire will turn to, and as well as blue sapphires, you can also get yellow and oranges ones. Heat treatment is the most popular sapphire enhancement, and it requires heating the gemstones to between 1600 and 1800°C. The length of time you heat the gems can also affect their colour, and it can take up to 20 hours, depending on what colour you are looking to achieve and the chemical composition of the sapphire.
It is extremely rare to get a perfect gemstone that does not have any imperfections, and it is the same with sapphires. They can often contain cracks and inclusions, which can affect the look of the sapphire and how it interacts with light. One thing you can do about this if heat treatment has not fixed the problems is fracture filling. The sapphires will be filled with glass to hide the cracks and inclusions, but this drastically reduces their value and is not a permanent fix.
Lattice diffusion is another form of heat treatment that you can use on sapphires, and it can dramatically change the appearance of the sapphire. The sapphires are heated to extreme temperatures, almost to their melting point, and then chemicals are added that will change their appearance. The chemicals most commonly used in this process are beryllium or titanium, which will change the gemstones’ colour and appearance. However, in most cases where a sapphire has been treated like this, the effects are not permanent, and the changes are only superficial.
It is estimated that around 98% of sapphires on sale in the jewellery industry have been enhanced somehow> It is a common practice that has been done for hundreds of years. The enhancement of sapphires can make them much more appealing and can make them look stunning when made into beautiful jewellery.