Diamonds are screened for treatments and natural origin in every step of the process. Gemologists are trained to identify the "telltales" that indicate a gemstone may have been treated or is synthetic.

If these are found, the stone is immediately sent to the Gem I.D. Department. Following Color and Clarity Grading, all diamonds are sent for Gem I.D. Examples of diamond treatments are coating, fracture filling, laser drilling, high pressure high temperature treatment and artificial irradiation.

Colored stones are sent to the Gem I.D. Department for identification, color origin determination, country of origin, and to check for treatments.