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The Jewelry Judge – Identifying Pearls

Jewelry Judge Ben Gordon - Pearl IDPearl is the Birthstone for June and the 30th wedding anniversary. The Jewelry Judge shares his knowledge and experience with clients everyday.

How do you tell the difference between a natural pearl and its cultured cousins?

Do you know the difference between freshwater cultured pearls and Japanese Akoya?

Pear Necklace

The most valuable cultured pearls are saltwater pearls that originate from oysters of the Pinctada family and include Akoya, Tahitian and South Sea varieties.  They are prized for their nacre, the iridescent outer layer of the pearl, and satiny luster.

Pinctada fucata is the species of oyster used by Kokichi Mikimoto, the Japanese pearl farmer and entrepreneur credited with creating the first cultured pearl.

OysterCultured pearls are created by taking a spherical bead nucleus, inserting it into the oyster to provide a catalyst around which the nacre grows, forming a pearl. If a bead nucleus is present when looking down the drill hole, this is confirmation of a cultured origin.

Pearl StrandsChina uses mussels in farming the freshwater cultured pearls they produce in large quantities. Freshwater pearls are usually more affordable than saltwater cultured pearls and they are available in a wide range of prices, shapes, sizes and colors. Tissue-nucleated freshwater pearls are mainly baroque with some variations while bead-nucleated pearls are mostly semi-round to round.

There are many pearl look-a-likes (imitations) on the market including plastic, shell-coated beads, mother-of-pearl beads and even glass beads that contain ground fish scales called ‘essence d’orient’.

Identifying Pearls:

  1. Rub the pearl across your front tooth, it should feel gritty, not smooth.
  2. Rub two pearls of a strand together, once again they should feel gritty, not smooth.
  3. Evaluate the drill hole. The pearl’s drilled hole is a smooth cross cut, while the faux bead will have a punched out appearance.
  4. Cultured pearls are not perfect in appearance. Faux beads are perfectly round and smooth without defects.
  5. Over time paint chips may be noted as faux beads age.
  6. Weight of cultured pearls is heavier than faux beads.

 

The sizes of cultured akoyas overlap those of freshwater pearls, but the superior luster and surface quality of akoyas will stand out when compared to freshwater pearls.

Caution:

  1. Be on the lookout for treatments that are used to enhance color. Inexpensive freshwater cultured pearls may be dyed black to imitate Tahitians or dyed gold to simulate South Sea golden pearls.
  2. Inspect the exterior surface of the pearl for concentrations of dye, or peer down the drill hole to determine if dyed after drilling.
  3. Sometimes lighter-colored Tahitians may be dyed or the bead nucleus irradiated so the pearl appears black.

Identifying pearl types and treatments can be a complex task.
See the Judge and he will share his expertise during a consultation.

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May Birthstone Emerald

emeralds-roughEmerald is the May Birthstone, as well as, the 20th and 35th Anniversary Gemstone.

When the Spanish came to the Americas, Europeans saw how beautiful emeralds were as Colombian emeralds were brought back to Europe by the conquistadors.

Today Emerald has moved back into its position as one of the “big three” gemstones, with  Sapphire (1st) and ruby (2nd).  New mines and increased production brings many beautiful gemstones from Zambia and Muzo in Colombia is now back in production. Both mining and selling will increase the availability of emerald in the market place.

Jewelry Judge Ben Gordon Double CheckKnow what you have by getting a Jewelry Judge Consultation.

It is common knowledge that Colombian emeralds (and other colored gemstones) are undervalued, since their rarity and beauty still catch the attention of investors. But over priced on-line sources are way too common. Like the diamond and other gemstones,  emeralds can be judged according to the 4Cs: color, cut, clarity and carat weight. These gems are highly prized and intensely colored ones can be quite rare, so make sure that you get a Jewelry Judge Appraisal Report or Consultation.

Most gemologists agree that it comes down to color, clarity and transparency when purchasing an emerald. Color should be evenly distributed and not too dark.

Determining if you have a Columbian Emerald is done using a Chelsea filter, which is basically a blue filter, that reveals hidden secrets in the different wavelengths of a gemstone. If the stone under the Chelsea filter looks pink or red, it is a Colombian emerald (Brazilian and African emeralds remain green due to iron content in the gem).

If the stone looks green, it is something other than Colombian emerald (tourmaline or green glass, etc.). This is because emeralds have a double peak spectrum, one in the red zone and one in the blue zone which cancel each other out and produce what our eyes detect as (Emerald Green).  The Chelsea filter takes advantage of this spectrum by blocking the blue part of the spectrum and only allowing the red or pink to come through.

emerald1Inclusions are a natural part of an emerald. Emerald is harder than quartz or tourmaline and resists most scratching and wear. It is not as hard as diamond and sapphire, and may be damaged if dropped or bumped hard. Small microscopic fissures are common to emerald due to the crystal structure.

The normal processing that takes place after cutting and polishing an emerald, includes the treatment of  fissures that reach the surface (if any), which are (Treated) masked with a colorless oil (usually Cedarwood Oil) or resin to reduce the visibility of those fissures. This simple and low-tech process is accepted as normal by the gem industry and is called clarity enhancement which may be minor, moderate or significant.

Emerald color is unaltered by this treatment and remains natural. Oiling does not detract too much from the overall value of the stone when inclusions are present. But it’s all about the color, hue and saturation of the gemstone!

Emerald2

Be Careful: Emeralds set in jewelry may last for centuries with the proper care. Since the many natural emeralds contain filled fractures, it’s risky to clean them in an ultrasound or with steam. Ultrasonic vibrations can weaken already-fractured stones, and hot steam can cause oil or unhardened resin to come out of fractures. Leaving you with an ugly looking gemstone. Because of this we do not recommend Emerald as a “Daily Wear” item such as an engagement ring, but rather as a social or event piece that you can show off on an occasional basis.

Cleaning: Use warm, soapy water coupled with a soft toothbrush and gentle scrubbing for the safest way to clean emeralds.

Trust has been the hallmark of our appraisal business, it is the reason our clients continue to bring their precious jewelry to us.

Mr. Gordon is an advocate for consumer awareness and demonstrates his community commitment by regularly delivering talks to educate and protect the public.