The gemstone market is vast and can at times seem quite complicated. On your gemstone journey, you may encounter the terms “treated” and “untreated” in relation to specific stones.

Overall, gemstones are technically altered by human hands as soon as they leave the ground. This is through the cutting and polishing process, which is the process that takes the mineral from a rough stone to a polished and sparkly gem we see in fine jewellery.

Treatments, however, refer to any process other than cutting and polishing that improves the appearance of the color or clarity, or that are used to alter the appearance, durability or value of a gemstone. Today, a majority of gemstones are treated to improve their appearance, with some of those treatments consisting of heat, irradiation, dyeing, oiling, or other processes.

Some of these enhancement procedures have been used for centuries, while others are recent. People in the gem industry always choose treatments based on the gem type and the desired effect.

Treating gemstones is generally an accepted practice within the industry, however, prices can be affected due to these circumstances. Overall, untreated and natural gems have a higher value than enhanced ones. This is due to supply and demand, for example, only 0.5% – 1% of sapphires are untreated. Therefore, natural untreated sapphires are far more uncommon and valuable than treated and chemically altered stones.

At Anpé Atelier, we use a mix of natural untreated and treated gemstones, and find that both produce an incredibly beautiful end result. The choice of choosing a treated or untreated gem is truly up to you and depends solely on what you value!

In this post we will discuss the most commonly used gemstones that we use at Anpe and what treatments they may or may not go through. If you want to dive deeper into the topic and learn more, then download our Ebook, “Gemstone Treatments.”


Nowadays it is estimated that nearly 99% of sapphires used in jewellery are treated with some sort of enhancement technique. For sapphires it is common to enhance them mainly through color and clarity. Some of the most common treatments for these gems are through heating, filling and irradiation.

Heating: The oldest and most common treatment for sapphires is through a heat treatment. The majority of the sapphires in the market- place have been heat-treated or thermally enhanced in furnaces. Heating is used to improve a sapphire’s color, remove color zoning, and improve clarity.

At Anpé Atelier we have a stock of both heated and unheated sapphire, but we never work with sapphires that have been exposed to filling or irradiation treatments.

The Kotuva ring holds a heated 3.25ct. cornflower blue sapphire, set in 18kt. white gold.


Emeralds are one of the softer and more delicate gemstones in the trade and actually tend to be the most included of all natural gemstones.

These inclusions are tolerated because the finest emeralds display a vivid bluish-green color that is unique in the gem world. But in many cases the various internal gas bubbles and cracks make the emerald look cloudy or milky.

Emeralds go through a number of enhancements in order to get a better clarity from the stones.

Oiling: Oiling is one of the most prominent treatments used to enhance an emerald’s appearance. Through a heated oiling process, it is possible to fill the inter- nal inclusions by applying oil to the surface through high pressure, thus reaching the fissures. The result is improved clarity since the light performance of the filled cracks is similar to that of natural emerald.


While most tourmaline gems are untreated in the industry, the percentage of treated tourmalines is increasing. Tourmalines are one of the common gemstones that we use at Anpé Atelier, however we only use unheated and untreated tourmaline gems.

Tourmalines are similar to sapphires in that they come in a vast array of unique colors. Some of the common treatments for this gem are irradiation and heating.

Heating is usually used when a tourmaline is too dark in tone and results in a lighter, more attractive color.

Irradiation develops or intensifies either a red or yellow color in tourmalines. Depending on where the stone was mined, and what color it was to begin with, will determine how it reacts to the radiation treatment.


A relatively small percentage of gem-quality diamonds are treated. However, if they are treated, it is for two reasons: to improve clarity or to alter color.

Clarity: Laser drilling and fracture filling are the two treatments used to alter the clarity of diamonds.

Fracture filling is the most common treatment to enhance the clarity of a diamond. A molten leaded glass-like substance is infused into the diamond’s fractures, which in turn disguises small cracks. This enhancement can make a diamond look more attractive but it may decrease the color grade.

Color: There are a number of treatments that enhance the color of diamonds, which include: Irradiation, annealing, high pressure high temperature (HPHT), and coatings.