Client: – I would like to lighten up a bit this unique 35+ ct sapphire…
Me: – To cut a full faceted crown with only 0.5 mm height? Hold my beer! 😎
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In this video I’m showing the re-cutting process of an important and very complicated stone. It is the most complex re-cut project I have done to date.
It is a natural unheated sapphire, weighing more than 35 carats, with the peculiarity that all its color is concentrated in a very thin layer on the crown. These sapphires, originated from Sri Lanka, are known as “ottu sapphires”, they have a very irregular color distribution, with a practically colorless crystal center and a very dark outer layer.
The need for the re-cut of this stone was because the color of this sapphire was too dark. The stone looked almost black when viewed from the crown. My friends at Antonio Negueruela Gems were wondering if it could be lightened a little by re-cutting.
The complexity came from the fact that the crown was already very shallow, only about a millimeter and a half! The thickness of the colored layer needed to be reduced a just little, without going too thin and the stone losing the intensity and homogeneity of its color.
In addition to having a very thin colored layer, the stone had some very fine fissures that could complicate the work. If any particle of the material close to those fissures had jumped off, it could force me to cut more than necessary to remove the cavities on the crown, with the risk of losing the optimal color of the stone.
After each little touch-up, I had to un-glue the stone from the dop to see its color, because with the stone stuck to the dop you can’t see its color properly. Light does not reflect from the pavilion and the color appears less saturated while the stone is glued. In the end, I glued and unglued the stone to the dop more than twenty times throughout this re-cutting work. It took me seven whole days to complete this project, but the result is worth it.
If before we had a blind and practically black stone, the color after re-cutting is a beautiful saturated Royal Blue. The stone has jumped to another league! With this extremely thin crown I managed to give it the complete faceting and keep the uniformity of color throughout all the stone! In daylight it looks fantastic, even better than with artificial light! It is a truly unique sapphire, for its size, clarity and color distribution!
There are many blue sapphires in the world, but it would be extremely difficult to find another sapphire with these characteristics! It is a stone for collectors of truly unique gems!