Emerald - Oil Treatments

    Jan 99:  The First Emerald Congress held  in Bogota, Columbia concluded the only adequate treatment for emeralds was cedar oil.

    Today, most emeralds are typically treated with a variety of substances in an attempt to hide or mask fissures within the gemstone.

    Antonio Negueruela markets a purified cedar oil in which the color is suppressed. The oil has a high density and a refractive index similar to that of emerald.

    One source uses a process similar to this:

    "The emerald is to be placed in a container and covered with alcohol. The alcohol is to be heated slowly up to a maximum temperature of 50 C in order to remove any foreign substances. Once the emeralds have been cleaned, they are to be placed in a glass container and covered with the purified cedar oil to a minimum of 3 centimeters above the top of the stones. The container is then heated slowly up to a maximum of 90 C and then left to settle to room temperature over a period of 12 hours. Once the liquid is cold, the emeralds are to be removed and placed on a clear absorbent paper. Then they are to be dried with a cloth and then rubbed with a duster."

    This description is similar to the process by which Opticon or other epoxy is used to treat an emerald. The use of an epoxy filler differs in that an epoxy sealant is placed on the top of the gemstone to seal the fissures containing the resin.


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