DCGIA President – Kusam Malhotra & Helen Serras-Herman
Helen compared natural gem materials against the simulants available in today’s market. She provided slides of Sonora Chrysocolla, Turquoise, Lapis, Azurite with Malachite, and natural drusy gemstones alongside simulants made to imitate these natural materials.
The term “simulants” refers to natural or enhanced materials that simulate another natural gemstone. Simulants and imitation materials are not new, in both ancient Egyptian and Roman times, lesser materials were used to imitate turquoise, and green glass was used to imitate emeralds.
There are many materials on the market being made or enhanced to look like some other natural material, especially materials that are rare, expensive or in high fashion demand. These simulants, or “look-a-likes”, provide an inexpensive alternative to the natural gems, and many of them are beautiful and durable enough to be used in jewelry designs.
Simulants may be made using the identical natural material, a cheaper imitation material or a man-made material, and generally fall into the following categories:
Stabilized Material – Lower quality natural material is mixed with resin in order to harden the stone, so it survives the cutting and polishing process, without falling apart. Stabilization may also deepen the color. Stabilization requires high pressure to allow the resin to be absorbed into the rock permanently. Visit Colbaugh Processing Inc.
Blocks by Colbaugh Processing
Treated Material – When natural material is mixed with resin and dyes are added, then the material is referred to as “treated” instead of “stabilized”.
Compressed Material – Small nuggets of the natural quality material are compressed with resin into blocks. The outline of each natural nugget is still visible.
Natural Azurite-Malachite carved by HSH
Azurite-Malachite Compressed Blocks
Reconstituted Material – Natural material, usually of low quality, is crushed into powder, mixed with resin, often along with dyes, then poured and molded into blocks. The final block product is easy to slab and shape into cabochons. Reconstituted blocks of low grade natural materials- turquoise, coral, azurite and others, offer an inexpensive option for lapidary materials.
Man-Made Material – Plastic resin imitation blocks dyed in various ways to imitate many natural gemstone materials are also available on the market. There is no natural material present, so they are inexpensive options for natural lapidary materials.
Natural Sonora chrysocolla (left x2) beside Simulant (right x2) – cabs cut by Keith Horst
Natural – Drusy Gem Materials
With all these types of materials available, visual identification is neither accurate nor reliable. Always ask the vendor about the materials used, and get the answer in writing. Always buy from a reputable vendor that will stand behind their products, and are able to supply information on the identity and source of the material.
Dyed Drusy Quartz – cabs cut by Keith Horst
Dealers should always disclose treatments and enhancements. While the original wholesaler or lapidary may have disclosed this information, somewhere along the process from rough to cut, from design to sale (especially online) disclosure information gets blurred or lost.
The importance of disclosure, besides honesty and ethics, is in knowing how to take care of the finished stones, how well will they wear once set into jewelry, will they fade in the sunlight, dissolve in chlorine, will they survive ultrasonic cleaners or heat from the jeweler’s torch.
Helen Serras-Herman is an acclaimed gem sculptor with over 33 years of experience in unique gem sculpture and jewelry art. Her award-winning artwork has been exhibited world-wide and published in over 170 trade magazines and books. See her work at www.gemartcenter.com.
DCGIA Members thank Helen for sharing her knowledge and experiences with us.
Summary – Charles Marts
Pictures – Helen Serras-Herman
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