Types of Enhancements

Over 99% of emeralds have surface reaching fractures that are treated with oil, wax, resin, or something entirely unknown. This is done to improve the clarity & colour of emeralds, and usually termed as enhancement instead of treatment is the sales sector of the gem industry.

Types of enhancement includes but not limited to oiling, resin, glue, coloured oil etc. Most emeralds are oiled as part of the post-lapidary process, in order to fill in surface-reaching cracks so that clarity and stability are improved. Cedar oil, having a similar refractive index, is often used in this widely adopted practice. Other liquids, including synthetic oils and polymers with refractive indexes close to that of emeralds, such as Opticon, are also used.

The least expensive emeralds are often treated with epoxy resins, which are effective for filling stones with many fractures.