Clarity Enhancement Demystified

At DJU we are frequently asked about the process of clarity enhancement that we use on our diamonds. Clarity enhancement uses fracture filling or laser drilling to improve the appearance of a diamond, either by removing the inclusion or by making it less visible to the naked eye.

Fracture Filling

Fracture filled diamonds are those whose feathers have been filled in to enhance their brilliance. The process for fracture filling diamonds was developed in the 1980s and involves filling surface-reaching feathers with molten glass to improve the diamond’s clarity. Yet, it was not until the 1990s that fracture filled diamonds began to appear in the market in abundance.

The glass used has a high refractive index similar to that of diamond, making the fractures less visible when light passes through the stone. The treatment is performed under high heat and pressure, sufficient to force the liquid glass into the feathers. This method improves the diamond’s clarity but it does not affect its colour. Many diamonds contain minute feathers that do not pose a threat to the integrity or durability of the diamond. This is why we offer a lifetime guarantee on the durability of all our diamonds.

Fracture filling is a permanent treatment that can only be reversed if the diamond is exposed to extreme heat or acids.

Laser Drilling

Another method of clarity enhancement is laser drilling. This involves drilling minute channels in the diamond from the surface to an interior inclusion using a laser beam. The inclusion can then be removed by melting it with heat or dissolving it with acid. Laser drilling is usually used to remove more obvious inclusions such as black carbon spots that lie deeper within the diamond. The change in clarity is permanent.