Today all reputable jewelry organizations require full disclosure of laser drilling and the FTC is considering a revision of its guidelines. The tell-tale signs of laser drilling can be easily detected with proper training. The drilling process leaves a small tunnel from the surface of the diamond to the site of the former inclusion. Although minute, these tunnels can be readily seen with proper magnification and when you know what to look for. Of course, the technology of diamond enhancements keeps moving forward.
All diamonds have minute fractures and fissures.
When the fissures are large and numerous they can detract from a diamonds beauty and value. In lower grade diamonds these fissures can give the diamond a cloudy, whitish appearance and may be visible to the naked eye. In the late 1980s a new process was developed to hide the fissures. Although the composition of the filler is kept a secret, it is formulated to mimic the color and optical properties of the diamond being treated. As a result, the fissures in a fractured-filled diamond become less visible.