Treated Flux-Grown Synthetic Rubies

It has been reported that flux-grown synthetic rubies using the Kyropoulos Method have been treated by inducing rutile 'silk' similar to those found in the natural untreated rubies + it's a spin-off product. The treatment (s) is detectable by experienced gemologist (s) + 3 carat plus size stones are already in the international market and sold without disclosure.

(via Tairus) Kyropoulos Method
Chemically pure Al2O3 powder is used as raw material. A unique technique of raw material preparation allows sapphires to grow with Al2O3 purity, up to 99.997%. The whole growth process (25 kg sapphire crystal) takes 14 days and is controlled automatically. Raw material is loaded into the growing station, where optimum conditions are maintained. The essence of the improved Kyropoulos method is that sapphire crystal sprouts deep into the melt and during the process of crystallization. The crystals become cylindrical-shaped due to the formation of shrinkage cavity. The occurrence of shrinkage cavity is due to the difference in the densities of the liquid and solid sapphire ( 3 and 4 gm3 accordingly). Maintenance of the required diameter of crystals is carried out by automatic displacement of the seed crystal (without rotation). During the process the crucible is fixed. The pace of the draw of the crystal is lower than the pace of crystallization. As a result, only a small layer adjoining the growing surface, not the whole crystal, is in the melt. Thermal gradient, which provides the growth of crystal is maintained by the furnace construction that gives wedge-shape form to the crystallization front. The melt in crucible is achieved through resistive heating. Decreasing capacity on a heater is carried out with the use of precision system for capacity adjustment. Coating of crystals occurs in the same zone of growth inside the crucible. Such method allows the crystals to grow with minimal mechanical stress.