To maximize appearance and wearability, gemstones are often treated according to the gem type and the desired effect. Due to the rarity and uniqueness of colored gemstones, most high-end jewelers use various techniques to enhance gems. Some of these procedures have been around for centuries, while others are more recent developments.
What is Enhancement?
There are many ways to enhance the color, clarity, and durability of gemstones, thereby maximizing their beauty. The methods of enhancement vary depending on the type of gemstone and the final goal.
Gemstone Treatment and Enhancement
Heat Treatment
Heat treatment is a method of permanently enhancing the color and/or clarity of a gemstone through heating. The temperature and duration required to change the gemstone's color vary by type. For instance, rubies and sapphires require more heat than other gems. While some gems become more color-saturated after heat treatment, others like amethyst can fade when subjected to high temperatures. Some might worry that high heat could damage gems, but most gems form at high temperatures, so heat does not have a negative effect. Heat treatment is one of the most common practices in gem enhancement, and without it, the supply of quality gems would be significantly reduced. Therefore, it is an accepted practice by the jewelry industry and the American Gem Trade Association.
Infusion
Infusion involves filling gems with materials like oil, wax, glass, or resin to improve clarity. Like most gem enhancement procedures, this method dates back centuries with the aim of enhancing the gem's overall appearance to the naked eye.
Coating
Coating adds an additional protective layer to gems, varying in form and function. One of the most common materials used for coating is wax, which can improve the gem's luster and protect it from external oils and other damage. In other cases, synthetic polymers, resins, and oils are used to coat gems, improving both toughness and appearance. Coating is often applied to gems cut as cabochons, like turquoise and jade, and is common for pearls.
Bleaching
Bleaching is typically used to lighten the appearance of gems. Chemicals like bleach and hydrogen peroxide are among the most common whitening agents for gemstones. Bleaching can also remove unwanted colors to make the gem's appearance more uniform. This is a relatively stable enhancement method for gems that won't be recut or repolished post-treatment, but bleaching might negatively affect the gem's durability. Thus, bleaching methods are often combined with impregnation treatments to increase strength and durability.
Dyeing
Dyeing involves adding colorants to gems to give them new colors, enhance existing colors, or improve overall color uniformity. Since color is the most significant attribute of a gemstone, dyeing is one of the oldest enhancement methods. Some believe dyed gems diminish in value and authenticity, but this treatment only enhances their natural pigmentation — dyed gems can look nearly identical to much more expensive, untreated gems.
Irradiation
Similar to heat treatment, irradiation is an enhancement method that uses radiation to alter and improve the color of gemstones. Irradiation involves a degree of ionizing radiation that changes the atomic properties of the gem, significantly enhancing its appearance. The most common concern about irradiation is whether it's safe for the wearer, and the answer is yes! There's no evidence that wearing irradiated gems causes any harm.
New and Future Enhancement Techniques
Gemstone enhancement techniques have been around for centuries and continue to evolve each year to offer the most beautiful gemstone jewelry at affordable prices. We are committed to working with the best industry professionals and gemologists to maintain our high-quality standards in gem enhancement.
What to Look for When Buying Enhanced Gemstones
- Vibrant colored gems might have been heat or radiation treated. - Uniform colored gems might have been dyed or bleached. - Flawless appearance to the naked eye; if a gem looks exceptionally clear, it might have been infused.
Our Colored Gemstone Enhancement Methods
We are proud to offer the highest quality, hand-selected gemstones on the market. To meet our high professional standards, our colored gems undergo thorough examination by our expert gemologists to ensure all enhancements are precisely and carefully crafted.
Common Gemstone Enhancements
- Agate - Heated or dyed to improve color.
- Amber - Heated to improve color and clarity.
- Amethyst - Heated to improve color.
- Apatite - Heated.
- Aquamarine - Heated to improve color and clarity.
- Black Diamond - Heated or irradiated to change color.
- Black Onyx - Dyed.
- Black Spinel - None.
- Blue Topaz - Heated and/or irradiated to change color. Heat treated for color change.
- Carnelian - Heated to improve color.
- Chalcedony - Dyed.
- Chrome Diopside - None.
- Citrine - Heated to improve color.
- Coral - Coated or impregnated with colorless substances to improve surface uniformity or durability. Bleached or dyed to enhance color.
- Diamond - None.
- Emerald - Infused to improve clarity and/or color.
- Fire Opal - None.
- Garnet - None.
- Iolite - None.
- Kunzite - Heated or irradiated to improve color.
- Labradorite - None.
- Lapis Lazuli - Dyed.
- Moonstone - None.
- Morganite - Heated to improve color and clarity.
- Opal - Coated to alter surface consistency and durability.
- Pearl (Natural and Cultured) - Bleached, dyed, polished, and coated.
- Peridot - None.
- Prasiolite - None.
- Quartz - Green/Lemon: Irradiated to improve color. Smoky: Heated to improve color. Blue: Dyed. Rutilated/Pink/White: None.
- Ruby - Heated and/or infused to improve color and clarity.
- Sapphire - Heated and/or infused to improve color and clarity.
- Spinel - None.
- Tanzanite - Heated to change color and clarity. Infused to change color and clarity.
- Tourmaline - Irradiated to improve color.
- Turquoise - Coated or impregnated with colorless substances to improve surface uniformity or durability.
- White Onyx - None.
- White Topaz - None.