The Differences Between Heated and Unheated Gemstones

If you have been searching for an engagement ring or precious gemstone gift you may have come across the terms 'heated' and 'unheated' gemstones. Have you ever wondered what's the difference between heated and unheated gemstones? We think it is very important you have as much information as possible about the gemstones you are buying so in this blog we will discuss heated v unheated stones, anything you need to know and if it matters.

There are many common gemstone treatments, heating is one of the most widely accepted. Some people view it simply as the next step of the gemstone’s formation seeing as the heat could have been applied by the earth before they were mined. The difference between unheated and heated gemstone is simply a heated gemstone has been exposed to extremely high temperatures to improve the appearance of the stone and the intensity of the colours. The most regularly heated gemstone family is corundum, which most commonly includes ruby and sapphire. Other gemstones like citrine, tanzanite and aquamarine are also commonly heated.

To the naked eye there is absolutely no difference between heated and unheated stones. If you are looking at a sapphire engagement ring and one stone has been heated and the other has not you will definitely not be able to tell with the naked eye.

It’s an industry-wide norm for most sapphires to be heated to intensify their colour and remove imperfections improving their clarity. Unheated gemstones are simply the same as when they came out of the ground, they have not been exposed to any heat. We have some incredibly beautiful unheated gems in our latest batch of one of a kind engagement rings, including Entwined Green Bicolour Sapphire Solitaire Engagement Ring,  Three Stone Teal Sapphire Curved Engagement Ring and the Emerald Cut Sapphire Solitaire Engagement Ring.

When shopping, you can assume every sapphire has been heated unless it’s specifically labelled as 'unheated'. If a jeweller knows for certain a stone is unheated, as we do with some of our engagement rings, they often put that information on the product listing for transparency and as a selling point.

Gemstones are heated in the first place because only around 1% of all sapphires are of 'gem-quality' without heat treatment. If we were to only use that 1% of the sapphires that were mined, 99% would be discarded. That would be an incredible waste of our planets precious resources, plus it would not be nearly enough to meet consumer demand. This being the case we can appreciate the untouched beauty (besides the cutting of course!) of an unheated gemstone but we also celebrate this treatment that allows more gems to be worn and appreciated which would otherwise go to waste.

Because unheated gemstones are more rare there is an increased price attached to them above the more common heated gemstones of the same colour and quality. Being less rare than unheated stones they will likely not appreciate in value in the same way, however, you will get a more vibrant, colour saturated stone for your budget if you choose a heated gemstone and most are clean and clear with no inclusions visible to the naked eye. Unheated sapphires will have whatever inclusions were naturally created within them, we do in fact love these inclusions, they are like a fingerprint or universe within the gemstone, it's what makes each one completely unique.

Heated or unheated we marvel at the beauty that comes from our Earth and the people who mine them. You can rest assured the natural gemstones we sell have been responsibly scoured and their origin can be traced. If you ever have any questions or concerns about our gemstones please get in touch.