Common Gem Treatments

Two commonly "accepted" colored gem treatments are the "oiling" of emeralds and the "cooking" of sapphires and rubies. Know what to look for and what to buy.

(1) Oiling Emeralds

Nearly all natural deep green, beryl emeralds (genuine emeralds) have extensive internal flaws. The appearance of these stones can be markedly enhanced by placing in a vacuum chamber and immersing them in cedarwood oil (or another colorless oil). When the vacuum is removed, the oil is pulled into the minute spaces between fracture planes, making them less visually apparent. This process also allows light to travel further in the stone without interruption, which results in the stone having a richer, more vibrant color, often several shades darker than before it was oiled. This treatment can produce a remarkable change in the appearance of an emerald, greatly enhancing the beauty and clarity of the stone. Sufficient treatments may transform a light green, or off-green aquamarine into a much more valuable emerald. Both are beryl gemstones, so in theory, the treatment is a legitimate process. However, over time, cedarwood oil can leak out of the stone. It may be necessary to retreat the emerald every few years. In recent years, several alternative filling materials have come to market. The most famous is "Opticon." Opticon and other epoxy rosins are used in conjunction with hardeners. This results in a more permanent treatment, however, they can sometimes discolor, and may be impossible to completely remove for retreating the stones.

(2) Heat Treating Sapphires and Rubies

Sapphires and rubies are now almost always subjected to high heat in a gem furnace to improve their transparency and color. A well-known side effect is increased brittleness of the gems. This can result in the facet edges becoming abraded more rapidly that they otherwise would. Unless accompanied by a recognized gem lab report such as one from the American Gem Lab (AGL), you should always assume that your rubies and sapphires have been heat treated. Please see my guides on multi coloured sapphire treatments for the latest updates on sapphire treatments in the industry.

(3) Fracture Filling

As opposed to oiling (which has become an "industry-standard" practice, i.e., something most jewelers will not disclose), fracture-filling of emeralds and glass-filling of rubies is a controversial, yet also common, practice. Always ask if you suspect a gemstone may be filled, and keep a copy of the response just in case.

Disclosure: Your Right to Know

You may have heard of a recent lawsuit that arose over a treated emerald. The NBC program "Dateline" reported on it. The case centered on whether the treatment, which was disclosed to the buyer of a $14,000+ emerald and diamond ring, hid (by the owner, knowingly) an inherent weakness in the stone (the emerald was later damaged by the owner). The insurance company, State Farm, successfully claimed that it did, and denied payment. The owner then sued the jeweler. The buyer won a large award in the settlement. After the fact, you may not be so lucky. It's more likely that you'll just get stuck with an inferior stone and have no recourse but to pass the luckless stone on to your children in the hopes it makes it to vintage status, LOL.

At Eternal Pearl, I am always willing tell you about any treatment or enhancement that your stone may have had before you buy. And you're fully protected by our 3-way "no quibble" money back guarantee – 1. If you are unhappy, we are unhappy, 2. No objection is too small, 3. Expert outside opinions must be recognized and respected. If I have not disclosed enough information in the listing, please ask whatever specific question you may have about any item in my shop. My store is one of the largest handmade shops on eBay, and sometimes, I fail to say everything I know about a gemstone. Any other reputable dealer, on eBay or elsewhere, will similarly answer and indulge any question you may have about a precious gemstone or jewelry item, before or after you buy. Expect to be respected. Genuine investment gemstones should last the length of your lifetime in the current setting at least, longer in most cases not considering catastrophic accident. Any reputable dealer, will be patient and allow adequate time for your satisfaction to be complete. Gemstones do increase in value over time, but for 100s of years, this market has been relatively stable in its valuations, so a few months for a buyer to get appraisals and assurances are not unusual or extreme.