From fine-cutting and polishing in Austria, the Nexus Diamonds go to our coating facility in Austin, Texas. The DN coating is much different from anything else available in the market today, and has been a multi-year development process.
The Diamond Nexus coating material is corundum and other proprietary materials which is substantial, visible under microscopy, and has important measurable physical characteristics. The coating seals the stone's surface, greatly lowers porosity and makes the Nexus Diamond impervious to outside contaminants. It also increases hardness and scratch resistance. The coating is not fully transparent, and the slight opaque and blue phase shift imparted brings the reflective and refractive index (called "brilliance and dispersion") of the Nexus Diamond almost exactly in line with a natural diamond. The coating also gives the slightest hint of fluorescence that the most highly prized blue-white diamonds exhibit. Your Nexus Diamond will not look blue in color; the blue phase shift adds depth and richness to the look of the simulant, but does not color it. The effect is out of the range of visible light. (We do, however, also offer a true blue colored Nexus Diamond, our Glacial Ice colored stone.)
The coating process is time consuming and costly. Each Nexus Diamond is taken through a four step process to completely sterilize the surface, as any contaminant will ruin the coating. The Nexus Diamonds are hand placed in a special tool that holds each stone separately and at the proper angle for coating. The Nexus Diamonds are placed on a rotating table in a vacuum chamber. All air is evacuated from the chamber and a micro atmosphere of nitrogen and other proprietary gases is introduced. Corundum and our other proprietary materials (the species) are placed within the chamber. An electron beam, which is capable of producing temperatures as hot as the surface of the sun, is focused on the species and it is evaporated into a plasma state. ("Plasma" is the fourth state of matter, the others being solid, liquid and gas. Plasma is a high energy electrically charged mixture of ions and electrons. It is the stuff of stars: all stars that shine are pure plasma. Plasma appears naturally on earth only in places like lightning bolts, flames, and auroras).
An ion assist beam is then focused on the Nexus Diamonds, causing a reverse in polarity and the molecules in the plasma species are attracted to the molecules in the substrate. The two materials fuse together and the coating is deposited and interlocked to the surface.
A Word on Stone Coating:
A lot of companies sell a common CZ and put a coating on their product as a way to differentiate it. Sometimes the language used is "diamond infused", "diamond hybrid" or "sealed in a diamond". The coating they are referring to is called "DLC", which means "diamond-like coating". This coating process has been around for years, and the "diamond" coating being referred to is "amorphous carbon" which is really pencil lead. When a CZ is coated with amorphous carbon, the coating must be exceedingly thin as to be essentially non-existent. Otherwise, the CZ would be discolored. Coating a CZ in this manner does not have any effect on the look or performance of the stone. The stone remains a common CZ.
Clean room preparation
Diamond Nexus placed
in coating chamber
Electron microscopy image of Diamond Nexus coating