Synthetic diamonds and their types

Currently, diamond synthesis for the production of jewelry inserts is performed by two main synthesis methods:

- growing crystals in a metal flux medium under high temperatures and high pressures;

- chemical vapor deposition (CVD).

All types of synthetic diamonds are reliably identified using a cathodoluminescence test and testing based on the excitation of luminescence under the influence of high-intensity ultraviolet electromagnetic radiation. However, in our opinion, from the point of view of applied identification, in each of these two genetic types of synthetic diamond, it is advisable to distinguish three types of stones - in accordance with the manifestation of their identification properties.

For those synthesized by the flux method under the influence of high temperatures and high pressures:

- easily identifiable - having a characteristic growth structure and luminescent properties (manifested visually), or characteristic internal inclusions;

- requiring attention during identification – lacking characteristic luminescent properties (without additional cooling) and internal inclusions, but having a characteristic growth structure;

- requiring special attention and/or the use of methods that allow studying hidden features of the internal structure. As a rule, such stones have luminescence quenchers and/or have been subjected to processing that modifies the internal structure of the stone.

For stones synthesized by chemical vapor deposition (CVD):

- easily identifiable – having a characteristic growth structure and luminescent properties (manifested visually), the presence of characteristic internal inclusions is possible;

- requiring attention during identification – lacking characteristic luminescent properties (without additional cooling) and internal inclusions; however, the characteristic growth structure may be disrupted by processing that modifies the internal structure;

- requiring special attention or the use of methods that allow studying hidden features of the internal structure. As a rule, such stones do not have clearly defined characteristic luminescent centers, and their structural features are very weakly manifested (such stones, for example, include silicon-free monocrystals).