Radiation treatment
This treatment is done to change the color of the gem stones. Some gem stones have been radioactive after radiation treatment. The irradiated process to change the color of some gems is not stable / won't remain. (R.WEBSTER, Gems, fifth edition,) ''A recent examination of a green diamond treated with americium-241 oxide indicated that this stone was not only radioactive, but that it could not safely be worn until the year 5071."

A D-SDTC cut open to reveal the color of its depth

  Following is part of a letter sent by the Queensland Sapphire Producers Association to Australian Prime Minister John Howard and Queensland Premier Peter Beattie:
"a significant proportion of sapphires offered for sale here in Australia have been chemically modified by a bulk diffusion process which principally used beryllium, but may also include other chemicals such as lithium and titanium. During a recent Canberra gem show, we were visited by scientists from the Australian National University who had heard of this process and were enquiring as to whether it was really true that this was done. These ANU personnel advised us that beryllium is not only a highly toxic material, but all the beryllium salts are known to be carcinogenic . As a result of this, the release of any beryllium or vaporized salts during the high temperature treatment process would have significant health consequences, and there was even some concern that the very small residual amount in the treated gemstone may have lasting health consequences ".

Fracture filling treatment
Filling the surface reaching fractures and surface cavities, pits with additives improves clarity and or color. Flux or glass can also be used in this process adding extra weight, (price) to the real gem stone, this adding of weight / price is unacceptable. Emeralds commonly have their surface reaching cracks filled with resins, oleoresins however with or without hardeners the treatment is not stable.